Federation for the Science and
Division "Olive Oil"
Articles on Olive Oil
Books on Olive Oil
List of funded EU projects
Partner search for EU
Utilities and Tutorials
Selected Articles 1952-2006to search the page please press ctrl-F
To add an article please fill in this form.
Jump to 1950-1959 1960-1969 1970-1979 1980-1989 1990-1994 1995-1999 2000-2004 2005-
Authors De Soroa y Pineda JM
Title Technique d'extraction de l'huile d'olive sans pression et sans solvant
Journal Oléagineux Corps gras Lipides, 11, 621-623
Keywords extraction system;
Authors Bartlet JG; Mahon JH
Title Identification of Oils and the Detection of Oil Adulteration by Differential Infrarred Spectroscopy
Journal Journal of the Association of Official Analytical Chemistry, 41, 450-459
Authors Eisner J; Iverson JL; Mozingo AK; Firestone D
Title Gas Chromatography of Unsaponifiable Matter. III. Identification of Hydrocarbons, Aliphatic Alcohols, Tocopherols, Triterpenoid Alcohols, and Sterols Present in Olive Oils
Journal Journal of the Association of Official Analytical Chemistry, 48, 417-433
Abstract Olive oils; both foreign and domestic, were saponified, and the unsaponifiable matter was fractionated on a Florisil column. Gas chromatography of the first two hydrocarbon fractions confirmed that squalene was the major component of pressed and solvent-extracted pomace oils. However, iso- and / or anteiso- tetratriacontane was the major hydrocarbon in olive kernel oil. Hydrogenation and temperature programming indicated that there were several homologous series present, consisting of normal, iso- and /or anteiso-, and multiple branched chained hydrocarbons. Gas chromatography of the third Florisil fraction (tocopherols, high molecular weight aliphatic alcohols, and triterpenoid alcohol components) indicated the presence of three homologous series of normal iso- and/or anteiso-,and multiple branched chain alcohols. The triterpenoid alcohols were used to distinguish between pressed and solvent-extracted pomace oils. As little as 5% of pomace oil could be detected in laboratory-prepared mixtures. Campesterol and beta-sitosterol were the two sterols present in olive oils. The Fitelson test detected olive oils consisting entirely or largely of pomace oils.
Authors Galanos DS; Kapoulas VM; Voudouris E
Title Application de la Spectrophotométrie ultra-violette dans la région des 315 nm au controle des huiles: Détection de la Falsification de l'Huile d'Olive par les huiles de Grignons
Journal Revue Française des CORPS GRASS, 2, 291-300
Abstract Les auteurs étudient les caractéristiques du spectre d'absorption ultra-violette d'huiles d'olive; de grignons et de graines dans la région de 310-320 nm, où les tétraènes à doubles liaisons conjuguées présentent leur maximum d'absorption. Les résulté sont exprimés par le rapport des inclinaisons de la courbe, de part et d'autre des 315 nm (Rs). L'inclinaison de la courbe du spectre d'huiles d'olive pure et de graines alimentaires est régulière et la valeur du Rs est voisine de 1. Des huiles ayant subi une oxydation avancée et ayant até soumises par la suite à un traitement de raffinage, (cas des huiles de grignons et de quelques huiles de graines), présentent une valeur négative de Rs ou une très grande valeur positive, suivant le degré de l'oxydation qui a précédé le raffinage. Etant donné que la valeur absolue de leur absorption spécifique, dans ladite région, est de 10 à 30 fois supérieure à la valeur correspondante de l'huile d'olive, la falsification de cette dernière par des huiles de grignons, en proportion de 5 %, est facile à constater par la mesure du Rs.
Authors Cucurachi A
Title L'esame nel visible degli oli d'oliva vergini dei rettificati e delle miscele
Journal Rivista Italiana delle Sostanze Grasse, 46, 449-458
Abstract The A. has carried out the qualitative and quantitative study of virgin olive oil absorption in the visible; on 97samples of the 1967-968 crop, coming from different Italian oil growing regions. The investigation has put into evidence- as it was to be expected- the variability of such absorption depending on the factors: olive varieties, harvest period, oleification systems, etc., which modify the chlorophyll and carotenoids contents of the oil. Under experimental conditions the examined samples have furnished the following mean values - related to 1:1 oil solvent dilution- at the considered wave lengths 664=0,219; 606=0,069; 532=0,105; 474=0,726; 446=0,880; 414=1,018; 397=0,862; 375=0,695; The absence in rectified oils of absorption maxima at the considered wave lengths and in particular at 664 and 474 mm represents a useful circumstance in view of the evaluation of the virgin oil quantity present in olive oil and olive husk oil.
Authors Fedeli E; Baroni D; Jacini G
Title Sui componenti odorosi dell'olio d'oliva.-Nota III
Journal Rivista Italiana delle Sostanze Grasse, 50, 38-44
Abstract Prosiguiendo las investigaciones emprendidas sobre los componentes odorantes del aceite de oliva; se expone la aplicación de un método gas-cromatográfico preparativo, con el fin de eliminar algunos de los componentes cuantitativamente más significativos y previamente individualizados del citado aroma. El procedimiento consiste en aumentar la concentración de los componentes presentes en menor cantidad, haciendo, con ello, posible la práctica de su análisis GLC-MS. Operando como se acaba de indicar, es posible identificar otras substancias.
Authors Flath RA; Forrey RR; Guadagni DG
Title Aroma Components of Olive Oil
Journal Journal of Agricultural and Food Chemistry, 21, 948-952
Keywords Virgin olive oil; polar volatile components; codistillation; dry-column chromatography; gas-chromatographic-mass spectrometry; olive oil aroma; organoleptic assessment; Aroma; oil;
Abstract The polar volatile components of virgin olive oil were concentrated by codistillation with water; followed by solvent extraction and dry-column chromatography. Gas chromatographic-mass spectrometric examination of the polar concentrate yielded the identities of 77 components. Organoleptic assessment of some of these compounds indicated that several are significant contributors to olive oil aroma.
Authors Gutiérrez González-Quijano R; Cabrera Martin J; Gutiérrez Rosales F; Olías JM; Colakoglu M; Nosti M
Title Correlación entre métodos subjetivos y objetivos en la determinación de la calidad.-Problemas del aceite de oliva
Journal Afinidad, 31, 335-350
Keywords Aceite de oliva;
Abstract Los autores estudian la correlación entre los índices químicos legales (acidez; I.P. y K270) y los ensayos organolépticos de muestras de aceite de oliva y demuestran que dentro del periodo de inducción, aquellos son insuficientes para establecer un control aceptable en relación a la calidad-apetitosidad del aceite. Las técnicas de C.G.L. ofrecen cara al futuro un medio de valoración aromática objetiva. El estudio de las relaciones entre los'perfiles' de los aromagramas y las respuestas obtenidas por 'grupos de catadores' siguiendo las técnicas del 'Panel Test' muestran que estos pueden proporcionar datos concordantes en la valoración organoléptica de los aceites y que, por ahora, es la única solución práctica posible.
Authors Jacini VG; Fedeli E
Title Neure Untersuchungen der nicht-glyceridischen Bestandteile von Pflanzenfetten
Journal Fette Seifen Astrichm, 77, 1-7
Keywords non-glyceridic; vegetable fats;
Abstract The author give a comprehensive review on the non-glyceridic constituents of numerous vegetable fats with special reference to the research work in 'Stazione Sperimentale per le Industrie degli Oli e dei Grassi' since about 15 years. Initially; the research was concentrated on olive oil, owing to its great economic significance for Italy and other mediterranean countries; later on, the studies were extended to other vegetable oils. A large of substances classes were found and identified, which include aliphatic and aromatic hydrocarbons, aliphatic alcohols, terpenic alcohols and their esters, sterols and their esters as well as methyl sterols. Exact identification of these minor constituents required development of special techniques for separation, detection and identification, which are discussed individually. Furthermore, substances occurring in the olive are reported, which attract or repel the olive fly (dacus olivae). Some of these substances have odour and taste, such as aldehydes, aliphatic esters, hydrocarbons and furans, whose structures were elucidated by mass spectrometry. This work might be of interest with respect to measures for pest control.
Authors Gutiérrez R; Olías JM; Gutiérrez F; Cabrera Martin J; Del Barrio A
Title Los métodos organolépticos y cromatográficos en la valoración de las características aromáticas del aceite de oliva virgen
Journal Grasas y Aceites, 26, 21-31
Keywords Aroma; chromatographic; organoleptic;
Abstract Se comparan organoléptica y cromatograficamente (C.G.L.) muestras de aceites de oliva de distintas variedades y procedencias. Al estudiar cromatograficamente los volátiles; que constituyen el aroma de las muestras de aceite de 13 variedades de aceitunas españolas, se encuentran diferencias de orden cuantitativo que son estadísticamente significativas, en cuatro o mas componentes volátiles También se observan diferencias entre aceites de la misma variedad de aceituna procedentes de zonas olivareras distintas. Se deduce la dificultad que presenta la identificación de variedades y procedencias de los aceites, basándose en la composición cromatográfica de los componentes volátiles de sus aromas. Estos resultados deben ser considerados provisionales, ya que no se han tomado en consideración factores tales como las diferencias de maduración, ni las variaciones ecológicas.
Authors Vázquez Roncero A; Janer del Valle ML; Janer del Valle C
Title Polifenoles naturales y estabilidad del aceite de oliva
Journal Grasas y Aceites, 27, 14-18
Abstract El contenido en polifenoles de los aceites de oliva vírgenes varía normalmente de 50 a 500 ppm; expresadas en ácido cafeico. Existe una buena correlación entre la cantidad de polifenoles y la estabilidad A.O.M., pero no hay correlación significativa con los criterios objetivos de calidad ni con la calificación organoléptica de los aceites. Sin embargo existe una tendencia a que los aceites con alto contenido en polifenoles sean de buena calidad, de acuerdo con todos esos índices. Los polifenoles más importantes son el tirosol y el hidroxitirol. Este último parece ser el principal responsable de la acción antioxidante de los polifenoles.
Authors Spencer GF
Title Fatty Acids Composition as a Basis for identification of Commercial Fats and Oils
Journal Journal of the American Oil Chemists Society, 53, 94-96
Keywords Composition; Fats and Oils; fatty acids; identification; oil;
Authors Gutiérrez González-Quijano R; Janer del Valle C; Janer del Valle ML; Gutiérrez Rosales F; Vázquez Roncero A
Title Relación entre los polifenoles y la calidad y estabilidad del aceite de oliva virgen
Journal Grasas y Aceites, 28, 101-106
Keywords Organoleptic characteristic; polyphenol; stability; Virgin olive (oil);
Abstract Se demuestra que existe una buena correlación entre el contenido en polifenoles y la estabilidad A.O.M. de los aceites de oliva vírgenes. También existe correlación con las calificaciones organolépticas de olor y flavor de estos aceites. La presencia o ausencia de determinados ácidos fenólicos está relacionada con la aparición en el flavor de defectos o cualidades características de los aceites de oliva.
Authors Olías JM; Del Barrio A; Gutiérrez R
Title Componentes volátiles en el aroma de aceite de oliva virgen I
Journal Grasas y Aceites, 28, 107-112
Keywords Gas liquid chromatography / mass spectrometry; virgin olive oil (aroma); volatile components (determination); Aroma;
Abstract Los componentes volátiles en el aroma de un aceite de oliva virgen; arrastrado por nitrógeno, recogidos sobre carbón activo y extraídos con sulfuro de carbono, son separados e identificados por cromatografía gas-liquido y espectrometría de masas. Se identifican trece hidrocarburos, nueve alcoholes, tres aldehídos tres cetonas, cinco ésteres y un éter.
Authors Fedeli E
Title Caratteristiche organolettiche dell' olio di oliva
Journal Rivista Italiana delle Sostanze Grasse, 54, 202-205
Keywords organoleptic properties; olive oil; flavour;
Abstract The high accuracy of smell and taste organs in man, compared with instruments makes it exceedingly difficult to develop an objective means for assessing the flavour of olive oil, although its composition is, at least roughly, known. A selection is suggested to this problem, through the determination of certain, appropriately-selected parameters, and through a discussion of their choice.
Authors Solinas M; Di Giovacchino L; Mascolo A
Title I polifenoli delle olive e dell´olio d´oliva. Nota III: Influenza della temperatura e della durata della gramolatura sul contenuto in polifenoli degli oli
Journal Rivista Italiana delle Sostanze Grasse, 55, 19-23
Keywords olive; polifenoli;
Abstract Gli AA. hanno esaminato l'influenza che esercitano la temperatura e la durata dellagramolatura nel processo dilavorazione delle olive sul in polifenoli degli oli di resulta. per la ricerca sono state lavorate in frantoio olive della varietá a 'Coratine' mediante mature; 'Ogliarola di Bitonto' mature e 'Cellina di Nardò'raccolte da terra, adottando temperature (18 ºC e 30ºC) e tempi di gramolatura (0,30 e 60minuti) diversi. Sugli oli ottenuti sono stati dosati i polifenoli totali, `'idrossitirosolo, il tirosolo,l'acido caffeico,l'oleuropeilaglicone e tre fenoli non identificati, sostanze alle quali numerose ricerche attribuiscone a tre fenoli non identificati, sostanze alle quali numerose ricerche attibuiscono notevole importanza per lalor nfluenciza sulle caractteristche di qualitá e sulla stabilitá degli oli di oliva. I resultati ottenuti hanno messo in evidencza che i fattori natura e qualitá delle olive influiscono direttamente sul contenuto inpolifenoli degli oli di risulta.
Delle tecniche operative adottate nel processo di lavorazione ´'aumento della temperatura ha determinator l'arrichimento in polifenoli degli oli, mentre il prolungamento della gramolatura ha provocato la diminuzione di tali componenti. Dal calcolo de coefficienti di ripartizione dei polifenoli tra le fasi olio/pasta di olive si ricavano degli indici che assumono considerevole significato nel giudizio sulla corretta impostazione ed esecuzione de cicli di lavorazione.
Authors Olías JM; Dobarganes García MC; Gutiérrez F; Gutiérrez R
Title Componentes volátiles en el aroma del aceite de oliva virgen.II. Identificación y análisis sensorial de los eluyentes cromatográficos
Journal Grasas y Aceites, 29, 211-218
Keywords gas-liquid chromatography/mass spectrometry; Sensorial analysis; virgin olive oil (aroma); volatile components (determination); Aroma;
Abstract el presente trabajo estudia la composición química de dos aceites de oliva de distinta procedencia, clasificados por el método del «panel» como de calidad aceptable y rechazable.
La composición del aroma de ambos aceites fue estudiada por C.G.L.-E M encontrándose diferencias cuali y cuantitativas. La impresión sensorial de los componentes que se eluían de la columna cromatográfica era detectada mediante un grupo de cuatro jueces especializados.
Authors De Felice M; Gomes T; Catalano M
Title Estrazione dell'olio dalle olive con sistemi continui di centrifugazione delle paste. Risultati di ricerche triennali
Journal Rivista Italiana delle Sostanze Grasse, 56, 361-369
Abstract Results are recorded about the yields obtained during industrial processing experiments carried out on oil extracting plants operating on the principle of placing the olive paste under centrifugal force in direct contrast to the principle of using pressure only. With reference to these continuous systems the oil content in the olive foot and vegetable water; as ascertained over a of years through methodical investigation in also given; the quality characteristics and the autoxidation resistance of the oils produced is also stated. On the basis of available information we are discussing the possibilities offered by these processing systems, with regard also to improving the quality of virgin oil.
Authors Olías JM; Gutiérrez F; Dobarganes García MC; Gutiérrez R
Title Componentes volátiles en el aroma del aceite de oliva. IV. Su evolución e influencia en el aroma durante el proceso de maduración de los frutos en las variedades Picual y Hojiblanca
Journal Grasas y Aceites, 31, 391-402
Keywords Chemical characteristic; Olive (maturity influence); Organoleptic characteristic; virgin olive oil (aroma); Volatile components (evolution); Aroma;
Abstract El presente trabajo estudia la evolución de los componentes volátiles presentes en el aroma del aceite de oliva; durante el proceso de maduración, en muestras de las variedades Picual (Olea europaea rostrata) y Hojiblanca (Olea europaea arolensis) procedentes de menjibar (Jaén) y Lucena (Córdoba) respectivamente. Se hace un estudio de las variaciones de su acidez, índice de peróxidos, estabilidad A. O. M. y características organolépticas (puntuación absoluta de olor y sabor, perfil y perfil reducido de olor y sabor); de la evolución cualitativa de los componentes presentes en los concentrados aromáticos (sniffing) y, por último, se estudia la evolución porcentual de los compuestos que poseen significación sensorial.
Authors Dobarganes García MC; Olías JM; Gutiérrez R
Title Componentes volátiles en el aroma del aceite de oliva virgen. III. Reproducibilidad del método utilizado para su aislamiento, concentración y separación
Journal Grasas y Aceites, 31, 317-321
Keywords Gas-liquid chromatography; Reproductiveness (method); virgin olive oil (aroma); volatile components (determination);
Abstract A study of the reproductiveness of the method used for the isolation; concentration and separation of the volatile components of the olive oil is made, consisting in creeping with N2, adsorption on active carbon and further separation of the aromatic concentrate components by GLC. The results obtained are highly satisfactory, except for some chromatographic peak of small size or high retention time, since the confidence limits for the areas average are lower to the 5% of their value with a 95% of confidence coefficient.
Authors Damiani P; Burini G
Title Determination of the Triglyceride Composition of Olive Oil by a Multistep Procedure
Journal Journal of Agricultural and Food Chemistry, 28, 1232-1236
Keywords olive oil; procedure oil; triglyceride;
Abstract Olive oil was analyzed by separating the total triglycerides into fractions; different in the of double bonds per mole, by means of Ag+ TLC. The fatty acid composition -- overall and at the b position --was then determined both of total triglycerides and of single fractions; moreover, each fraction was oxidized and the products were separated by means of TLC into classes, each containing molecules having the same of azelaic acid residues (A3; A2S; AS2). The acids contained in each class were then quantitated by means of GLC. From the obtained data, the triglyceride composition of olive oil was determined (21 molecular species = 92.5% of total triglycerides), without the many ass assumptions usually conceived by other methods.
Authors Marzouk B; Cherif A
Title La Lipogenèse dans I´olive II. Formation des lipides polaires
Journal Oléagineux, 36, 387-391
Abstract Les lipides polaires de l'huile d'olive forment 2.5p 100 des lipides totaux. Ce sont des phospholipides (58 p. 100 des LP(*) et des galactolipides (42p. 100 des LP). Leur synthèse est accélérée du début jusqu'au milieu de la maturation et se traduit par des teneurs allant de 0.5 mg par fruit néoformé à 4.5 mg par fruit complètement mûr. Les acides gras caractéristiques des lipides polaires sont l'acide linolénique pour les galactolipides. L'évolution de ces derniers reflète l'apparition puis la perte progressives des capacités photosynthétiques du tissu. L'accumulation des lipides polaires évolue selon une courbe en sigmoïde comme pour les lipides neutres.
Authors Gutfinger T
Title Polyphenols in Olive Oils
Journal Journal of the American Oil Chemists Society, 58, 966-968
Abstract The levels of total polyphenols and o-diphenols were determined in virgin oils and in chloroform/methanol-extracted oils. The solvent-extracted oils were richer in polyphenols than the virgin oils. High polyphenol content was associated with a high resistance to oxidation of the oils. A linear relationship was found between polyphenol content and the oxidative stability of the virgin oils during storage at 60 C. After removal of the polyphenols; the oxidative stability of the oils decreased considerably and seemed to depend on polyunsatured fatty acid concentration.
Authors Itoh T; Yoshida K; Yatsu T; Tamura T; Matsumoto T
Title Triterpene Alcohols and Sterols of Spanish Olive Oil
Journal Journal of the American Oil Chemists Society, 58, 545-550
Abstract Nine Spanish olive oils; including three each of virgin (pressed oil), refined virgin, and B-residue (solvent- extracted pomace oil), oils from different commercial sources, have been analyzed for their unsaponifiable matter (USM). Four sterolic fractions separated from the oils have been analyzed by preparative thin-layer chromatography (TLC); these fractions are triterpene alcohols, 4-methylsterols, sterols and triterpene dialcohols. The compositions of the four sterolic fractions were determined as their acetates by gas-liquid chromatography (GLC) on an OV-17 glass capillary column. Identification of each component was carried out by argentation TLC, GLC and combined gas chromatography-mass spectrometry (GCMS); 44 components were identified, of which four: 24-methylene-31-nor-9 (11)-lanostenol, 24-methyl-31-nor-E-23-dehydrocycloartanol, 24-ethyl-E-23-dehydrolophenol and 5,E-23-stigmastadienol, were considered to be new sterols from natural sources. Several characteristics, including the content of triterpene dialcohols in the USM and that of C-24(28) unsaturated sterols in each of the four sterolic fractions, which can be used to distinguish between virgin and B-residue olive oils, were observed.
Authors Martel J; Alba Mendoza J
Title Influencia del método de obtención de aceites de oliva por centrifugación de pastas sobre su contenido en alcoholes grasos superiores
Journal Grasas y Aceites, 32, 233-237
Keywords aggregated water temperature (effect of); fatty alcohol (olive oil content); olive oil (obtainment); olive paste (centrifugation); olive storage degree (effect of);
Abstract Se ha realizado un estudio del proceso de centrifugación de pastas en relación con el contenido de alcoholes grasos en los aceites. En este estudio se ha tenido en cuenta tanto el estado del fruto como la temperatura del agua usada durante la centrifugación. Para ello se ha realizado un análisis de la varianza con dos tratamientos; según haya sido la aceituna utilizada, ya sea sana o atrojada y la temperatura del agua usada en el referido proceso de centrifugación, para la que se han usado tres niveles. Por lo que se refiere a los alcoholes grasos superiores, se deduce del análisis realizado, la influencia que sobre su contenido tienen tanto el estado del fruto como la temperatura del agua utilizada.
Authors Kapoulas VM; Passaloglou-Emmanouilidou S
Title Detection of Adulteration of Olive Oil with Seed Oils by a Combination of Column and Gas Liquid Chromatography
Journal Journal of the American Oil Chemists Society, 6, 694-697
Keywords Adulteration; olive; seed;
Abstract Samples of virgin olive oil and refined seed oils; as well as mixtures of olive oil with 10 and 5% seed oils were fractionated by column chromatography on silicic acid impregnated with ammoniacal silver nitrate. It was possible to isolate a characteristic fraction enriched in polyunsaturated triglycerides. Its linoleic acid content in pure olive oil never exceeds 9.3% whereas in pure seed oils, it varies between 38.1 and 70.1%; in mixtures of olive oil with 10 and 5% of seed oils, the respective values are 22.3-38.2% and 15.6-32.1 % The oleic-to-linoleic acid ratios of the same fraction are more than 7.6 (olive oil), 0.2-0.8 (seed oils), 1.1-2.0 (olive oil with 10% seed oils) and 1.4-3.6 (olive oil with 5% seed oils). These analytical values may be used as a safe criterion for the eventual adulteration of olive oil with seed oils.
Authors Kornfeldt A; Croon L
Title 4-Demethyl-, 4-Monomethyl- and 4,4_Dimethylsterols in Some Vegetables Oils
Journal Lipids, 16, 306-314
Keywords 4-Demethyl; 4-Monomehtylsterols; 4;4.Dimethylsterols; vegetable oils; wheat; olive; linseed; Composition;
Abstract The content of 4-demethyl-;4-monomethyl- and 4,4-dimethylsterols in 13 vegetable oils was found to vary between 0.10-1.4%, 0.01-0.08% and 0.02-0.29%, respectively. The largest amount of dimethyl-sterols was found in maize and wheat germen oils, whereas the largest amounts of the dimethylesterols were found in the olive in linseed oils. The predominating dimethylesterols were sitosterol, campesterol, stigmasterol and D5 -avenasterol. Among the 4-monomethylsterols, obtusifoil, gramisterol, cycloeucalenol and citrostadienol predominated, but usually more than 10 components were found in this fraction. The composition of the 4,4-dimethylsterol fraction was also rather complex, with the 9,19-cyclopropanesterols together with a- and b-amyrin predominating. In most of the oils, characteristically high or low percentages of some sterols were found, and a few specific sterols were also noted. A scheme useful for characterization is presented.
Authors Marzouk B; Cherif A
Title La Lipogenèse dans I´olive I.- Formation des lipides neutres
Journal Oléagineux, 36, 77-82
Abstract L´huile d'olive est formée de 97.5% de lipides neutres essentiellement composés de triacylglycerols; et de 2.5% de lipides polaires (phospholipides et glycolipides). L'acide gras caractéristique de l'huile d'olive est l'acide oléique qui forme à lui seul plus de 60% des acides gras totaux. Trois phases d'accumulation des lipides neutres ont été observées dans une courbe d'évolution en sigmoïde. Les diacylglycerols augmentent en masse dans l'olive jeune puis accusent une baisse dans les fruits mûrs.
Authors Gutiérrez R; Dobarganes MC; Gutiérrez F; Olías JM
Title Componentes volátiles en el aroma del aceite de oliva virgen V. Aceites obtenidos de frutos atrojados.
Journal Grasas y Aceites, 32, 299-303
Keywords Fusty olives chromatography
Abstract En el presente trabajo se aborda el estudio de los compuestos volátiles presentes en el aroma del aceite obtenido de frutos atrojados. En base a los compuestos identificados se puede destacar que en el fruto se produce una sobre maduración; una clara oxidación de los ácidos grasos insaturados y un ataque extremo por mohos y bacterias, siendo este último proceso el que tiene una importancia más destacada desde el punto de vista organoléptico.
Authors Badolato ES; Durante F; De Almeida EW; Silveira NV
Title Oleo de Oliva_ Avaliação de sua Qualidade
Journal Instituto Adolfo Lutz, 41, 63-70
Keywords quality control for cromatography in gaseous phase; detecção de fraude; iodine index and regression index; olive oil;
Abstract Existem algumas misturas de óleos que; pela composição de seus ácidos graxos, podem ser adicionadas a óleos de oliva, sem que essa fraude possa ser detectada pelos processos clássicos, pois os índices físico-químicos do produto final caem dentro do intervalo característico do óleo de oliva puro. A cromatografia em fase gasosa foi empregada para a obtenção do perfil cromatográfico dos ácidos graxos do óleo de oliva, do de soja e do de babaçu, bem como de misturas, preparadas no laboratório, de dois ou três dos referidos óleos.Foram também determinados os índices de iodo e de refração dos óleos puros e das misturas de óleos.Pela presença dos ácidos graxos caprílico, cáprico, láurico e mirístico, e pela composição relativa dos demais ácidos, foi possível detectar a presença de óleo de babaçu e de óleo de soja em óleos de oliva, mesmo quando os índices físico-químicos indicavam óleo de oliva puro. Durante o período de janeiro de 1979 a dezembro de 1980, foram analisadas 190 amostras de óleos de oliva, expostos ao consumo em São Paulo, provenientes do exterior, sendo que os óleos enlatados no pais de origem eram puros, enquanto que 42% dos enlatados no Brasil estavam falsificados.
Authors Tiscornia E; Forina M; Evangelisti F
Title Composizione chimica dell'olio di oliva e sue variazioni indotte dal processo di rettificazione
Journal Rivista Italiana delle Sostanze Grasse, 59, 519-556
Keywords rettificazione; variazioni;
Abstract Viene innanzi tutto riportata; allla luce delle piú recenti acquisizioni analitiche in tale campo di ricerca, la composizione chimica dell'olio ricavato dall' aolea europaea L., prodotto nel bacino del Mediterraneo. In via preliminare, i dati inerenti la composizione gliceridica sono stati elaborati mediante tecniche 'chemiometriche', tecniche che consentono di ottenere la massima informazione dai dati chimici mediante metodi matematici e statistice, che ne hanno permesso la rappresentazione differenziate, sotto forma de grafici bidimensionali, che conservano la maggior parte dell'informazione utile data dagli otto acidi grassi presenti in quantitá più elevata in tale olio. Inoltre, altre tecniche chemiometriche sono state utilizzate, al fine di valutare la posibilità di predizione della zona di origine di un olio dalla sua composizione in acidi grassi. In particolare, l'applicazione di tali tecniche nell?elaboracioen dei risultati analiciti inerenti la composizione in acidi grassi dell 'olio di oliva di pressione prodotto in sei regioni italiane, ha consentito una 'abilità predittiva' del 92%; inoltre nella metà circa dei casi di attribuzione errata, la successiva attribuzione errata, la successiva attribuzione (sulla base del 'voto di maggioranza') È risutata giusta.Viene quindi presa in considerazione l'influenciza esercitata dai processi di rettificazione sulle diverse classi di constituenti presenti nell'olio di oliva di pressione. A tal fine é stata presa in esame la componente gliceridica, in funzione particolarmente di accertare eventuali modificazione apportate alla specifica distribuzione degli acidi grassi sul glicerolo. Inoltre, è stata presa in considerazione anche l'influenza esercitata sulle diverse frazioni costituenti la componente 'non glicerica',con particolari riferimento a quella degli idrocarburi, degli steroli, degli alcoli tripernici ad alifatici, dei tocoferoli e dei componenti fenolici, nonchè sul contenuto in metalli e sugli eventuali residui di pesticidi derivanti dal trattamento antidacico.
Authors Tacchino Canuti E; Borgogni C
Title Indagine sul Contenuto di Alcoli Alifatici dell´olio d´oliva di Pressione e di Estrazione
Journal Rivista Italiana delle Sostanze Grasse, 60, 575-581
Keywords alcoli alifatici;
Abstract The research on the content of saturated aliphatic alcohols with linear chain C18; C20, C22, C24, C26, C28, has been conducted of samples of olive oil extracted in laboratory from olives grown in Liguria and belonging to two cultivars. For comparison, also commercial olive oils have been analyzed.
From the quality point of view, no difference in the content was ascertained between the oils obtained by extraction or by pressure, whereas considerable differences were found in the quantities. This element may possibly be used as an analytic datum for differentiating the two types of oil.
Authors Gegiou D; Georgouli M
Title A Rapid Argentation TLC Method for Detection of Reesterified Oils in Olive and Olive -Residue
Journal Journal of the American Oil Chemists Society, 60, 833-835
Keywords reesterified; oil; olive;
Authors Cortesi N; Fedeli E
Title I composti polari di oli di oliva vergine. Nota 1
Journal Rivista Italiana delle Sostanze Grasse, 60, 341-351
Keywords GLC-MS; HPLC; Polar components; TLC; Virgin olive oil;
Abstract Several samples of virgin olive oils have been extracted by MeOH-H2O and the extracts have been submitted to several analytical techniques in order to determine qualitatively and quantitatively the components. We have utilized HPLC; TLC both as analytical and preparative tools, GLC to identify known components and GLC-MS to identify unknown components by reference to synthetical compounds. In summary identification is referred to about 20 compounds. Several benzenoid derivatives have been identified which have strong influence on the palatability of the oil and which could also play a biochemical role as such or as antioxidants. The identified components are only a part of the polar substances of virgin olive oil and research are continuing to improve the knowledge.
Authors Forina M; Armanino C; Lanteri S; Calcagno C; Tiscornia E
Title Valutazione delle caratteristiche chimiche dell´olio di oliva in funzione dell´annata di produzione mediante metodi di classificazione multivariati.
Journal Rivista Italiana delle Sostanze Grasse, 60, 607-612
Keywords multivariate; olive oil classificatione;
Abstract Analytical data of samples of Portuguese olive oil of four years are tested. Two categories are characterized with chemometric methods (principal component analysis; multivariate bayesian analysis, SIMCA (soft independent modelling of class analogy): chemical-statistical model is built and the effect of the year on the typicalness of product, supplying an objective measure of ' quality-typicalness ' of year is obtained.
Authors Derde MP; Coomans D; Massart DL
Title SIMCA (Soft Independent Modeling of Class Analogy) Demonstrated with Characterization and Classification of Italian Olive Oil
Journal Journal Association of Analytical Chemistry, 67, 721-727
Keywords Characterization; classification; SIMCA; olive oil;
Abstract The multivariate technique SIMCA (soft independent modeling of class analogy) has been applied to the classification of foodstuffs on the basis of gas chromatographic profiles of some of their constituents. The data set used in this investigation consists of the percentage distribution of 7 fatty acids (7 variables) in 100 samples of virgin olive oil from 2 different regions (2 classes) of Italy; East and West Liguria. The SIMCA method can be used to compute whether an olive oil sample from Liguria originated in the western or eastern part of this region, while 98.8 % of samples that do not originated in Liguria are correctly classified as outliers. The developed classification rules are adequate for identifying oils according to their origin. Standard decision diagrams (SDD) are very attractive tools for classification of new samples; the similarity between a new sample and each of the classes is easily computed. Consequently, the SDD visualizes any similarity toward each of the classes, and enables a decision on whether the new sample originates in one of the regions under study.
Authors Mariani C; Fedeli E
Title Idrocarburi polyciclic aromatic hydrocarbons negli vegetal oils
Journal Rivista Italiana delle Sostanze Grasse, 61, 305-309
Authors Gracián J; Cota J
Title Estudio cualitativo y cuantitativo de la fracción de alcoholes grasos de los aceites de oliva y de los aceites de oliva y de orujo.
Journal Grasas y Aceites, 35, 358-363
Keywords Alcoholes grasos; Cromatografía gaseosa; Insaponificable; Oliva (aceite); Orujo de aceituna
Abstract The aliphatic alcohols fractions of a pressed olive oil and its corresponding foot cake oil; both obtained industrially, have been analyzed by gas chromatographic techniques. The fractions are constituted by linear chain saturated alcohols and their mono and di-unsaturated derivatives with chains from 18 to 30 carbon atoms. The differences between the fractions of both oils are only of quantitative character and some particularities can be applied to establish the analytical differences between them.
Authors Gutiérrez Rosales F; Risco MA; Gutiérrez González-Quijano R
Title Selección de catadores mediante el Método de 'Clasificación por Intensidad'
Journal Grasas y Aceites, 35, 310-314
Keywords Sensory analysis;
Abstract Se describe un método de selección de catadores para valorar la calidad del aceite de oliva virgen. Se examina la sensibilidad de 14 candidatos con los atributos atrojado; avinado, rancio y amargo, considerados como los defectos más comunes en el aceite de oliva. El método se caracteriza por su rapidez y economía.
Authors Montedoro GF; Garofolo L
Title Caratteristiche qualitative degli oli vergini di oliva. Influenza di alcune variabili:varietá, ambiente, conservazione, estrazione, condizionamento del prodotto finito.
Journal Rivista Italiana delle Sostanze Grasse, 61, 157-168
Keywords extraction; virgin olive oil;
Abstract The quality of an oil is to be considered under 4 aspects: a) as a commodity (genuineness, adulteration, alteration, etc., according to the prevision of the law); b) health (absence of foreign and toxic residues); c) nutrition and dietetics (chemical composition which fulfils the physiological and pathological needs of the consumer); d)organoleptic characteristics (chemical composition which makes it pleasant and appetizing). The later two aspects are particularly significant when dealing with “virgin” olive oils (extra and superfine). Infact the composition of the saponificable fraction (ratio: saturated fatty acids/unsaturated fatty acids and unsaturated fatty acids/linoleic acid) and de unsaponificable fraction (volatile and non-aromatic constituents and the presence of antioxidants) greatly affect the quality of these oils regarding the two above-mentioned aspects. Like all vegetal products, their qualitative features depend on several factors: variety, pedoclimatics, agronomy as well as technology harvest, extraction, conditioning). On the ground of the present report some of the above-mentioned points of view have been examined and their influence on chemical and organoleptic features have been taken into account. Three fundamental considerations have emerged from a comprehensive examination of the results: - in the first group of factors the grade or evolution of maturation of the fruit affects above all the organoleptic and marketable quality of the oil. – as for the technological operations, from the harvest onwards, preservation appears to be of great importance and seems closely connected to the first operation; - Phenolic constituents show a determining significance since they affect both organoleptic and nutritional features and, being responsible for oxidation stability (autoxidation) they also affect marketable features.
Authors Speek AJ; Schrijver J; Schreurs HP
Title Vitamin E composition of some seed oils as determined by high-performance liquid chromatography with fluorometric detection
Journal Journal of Food Science, 50, 121-124
Keywords concentration; detection; HPLC; mass spectrometry; olives; seed oils; soy beans; sunflower; vitamin E;
Abstract A high-performance liquid chromatographic (HPLC) method is described for the simultaneous analysis of E vitamers a-; and b-,g- and d-tocopherol and a-tocotrienol in seed oils. After diluting the oils with n-hexane, E vitamers are separated by HPLC and detected fluorometrically. Standardization is achieved, using electron-impact mass spectrometry and HPLC. Vitamin E composition of several hot and cold pressed seed oils, originating from maize germs, olives, soy beans and from sesame, safflower and sunflower seeds, was investigated. No clear differences were observed between E vitamer concentrations of hot and cold pressed oils of the same origin. On the other hand, vitamin E composition of oils different origin varied widely. Of the oils examined, only maize germ oil contained a-tocotrienol in detectable amounts (about 2%). Esterified E vitamers were not detected.
Authors Amelotti G
Title Problematiche inerenti la valutazione della frazione sterolica
Journal Rivista Italiana delle Sostanze Grasse, 62, 337-344
Abstract Some problems relevant the sterolic fraction evaluation in rectified sansa olive oil: The GLC analysis; of sterol fraction of 'sansa olive oils', using a capillary column, shows a very complex composition that however clarifies some interpreparative problems that arise when packed column are used. Since it has been shown that some GLC peaks well resolved by capillary columns, are artefacts of the refined process or have 'no sterol nature’, the calculation of the relative percentage of the sterols can be sensibly modified if the above components are taken into account. It is evident that to define the limits of the sterol composition of olive oils, the problem of including or excluding these peaks should be carefully considered.
Authors Mordret F; Morin O; Coustille JL
Title Détermination des flaveurs de corps gras
Journal Revue Francaise des CORPS GRASS, 32, 193-200
Keywords flaveurs de corps gras;
Abstract The evaluation of fat sensorial quality and particularly; the determination, of its flavor must take in accountants state: crude oil, refined oil, concrete fat, processed fat. There is a suited methodology in every case. The objectivity of the response, and consequently, the value of analysis is depending on the specialization and training of degustation jury. To strengthen these determinations, many works have attempted to bind the results of sensorial 0analysis and physico-chemical analysis. The gas chromatography of volatile compounds (aromagrams) offers the most of possibilities and, correlations have been established between degradation of flavor and appearance of a few components resulting from the oxidative alteration. The difficulties of such researches are owed to, at first, used slight quantities, volatility of analyzed components, and, particularly to differences of physicochemical and sensorial 'detectors' sensibility and specify. Considerable progresses have been carried out by the use of powerful analytical methods (dynamic head space, coupled gas chromatography/mass-spectrometry); but, in practice, the degustation is still the safest and the most rapids mean to control the edible fat flavor.
Authors Firestone D; Summers JL
Title Detection of Adulterated and Misbranded Olive Oil Products
Journal Journal of the American Oil Chemists Society, 62, 1558-1562
Keywords olive; Adulteration;
Abstract The Food and Drug Administration has been examining bulk and packaged olive oil products in a continuing program to detect adulteration of olive oil products. Thirteen of 20 products collected in 1983-84 labeled as olive oil contained undeclared esterified (synthetic) olive oil and four contained undeclared olive-residue oil (derived from olive pomace and pits). Seven of 13 brands of imported olive oil contained undeclared esterified oil; suggesting that considerable quantities of esterified oil have been shipped to the United States identified as olive oil.
Authors Maritano de Correche M; Oxley R
Title Composición en ácidos grasos totales, alcoholes alifáticos e hidrocarburos en materia grasa comestible
Journal Grasas y Aceites, 36, 88-92
Abstract El presente trabajo tiene como finalidad hacer un estudio comparativo de los alcoholes alifáticos y los hidrocarburos contenidos en el insaponificable y los ácidos grasos totales de materia grasa comestible. Los alcoholes e hidrocarburos fueron aislados; luego de la saponificación, por TLC y analizados por Callos ácidos grasos totales se analizaron por CGL derivatizados como ésteres metílicos. Existe una diferencia significativa entre los alcoholes alifáticos e hidrocarburos de la grasa de leche, la grasa de cerdo y el sebo vacuno. Es importante remarcar la diferencia entre el sebo vacuno virgen y el sebo vacuno comercial, atribuible a los tratamientos tecnológicos de obtención y refinamiento que modifican la composición del insaponificable.
Authors Brumley WC; Sheppard AJ; Rudolf TS; Shen CJ; Yasaei P; Sphon JA
Title Mass Spectrometry and Identification of Sterols in Vegetable Oils as Butyryl Esters and Relative Quantitation by Gas Chromatography with Flame Ionization Detection
Journal Journal of the Association of Official Analytical Chemistry, 68, 701-709
Abstract Electron ionization mass spectrometry (MS) of sterol butyrates is described. Fragmentation of common sterol butyrates is related to structure and is discussed in relation to the fragmentation of free sterols and of commonly used sterol derivatives. Derivatized samples of vegetable oils are introduced using a 10 m capillary gas chromatographic (GC) column for complete separation of the sterol butyrates. Quantitation of sterol butyrates in vegetable oils by packed column GC/flame ionization detection is based on percent relative area of peaks identified by MS. Results of analyses of sunflower; castor, rapeseed, and virgin olive oils, and other oils are presented. These techniques have been applied to the rapid screening of marketed olive oils for possible adulteration.
Authors Solinas M; Angerosa F; Cucurachi A
Title Connessione tra prodotti di neoformazione ossidativa delle sostanze grasse e insorgenza del difetto di ranciditá all' esame organolettico.Nota I
Journal Rivista della Società Italiana di Scienza dell´Alimmentazione, 14, 361-368
Keywords organoleptic rancidity; volatile components; headspace GLC analysis;
Abstract Relation Between chemical data and organoleptic rancidity With the aim to detect and determine the products giving the rancidity off-flavor to fats and oils ascertained by organoleptic test; the AA have carried on analysis by head space GLC and HPLC of penylhydrazones of volatile carbonyls on virgin olive oil undergone a conditioned oxidation. The volatile substances were extracted by nitrogen stripping a 37º C HPLC analysis of penylhydrazones of carbonyl compounds showed that acetone, butanal, esanal, eptanal and three compounds not yet identified.
Authors Cortesi N; Fedeli E; Tiscornia E
Title I componenti polari degli oli di oliva. Possibili utilizzazioni analitiche. Nota I
Journal Rivista Italiana delle Sostanze Grasse, 62, 281-286
Keywords Virgin olive oil; Polar components; Virgin oil quality;
Abstract Virgin olive oil polar components (CMP) have been previously studied and it was shown that they can be subdivided into two categories having high and low molecular weight. A relationship exists between said categories: low molecular weight compounds arise from cleavage of the high m.w. components. Both the categories can be utilized to characterize the different oils derived from olives. In particular during refining all of the cited components are hydrolyzed and eliminated. CMP and tyrosol (Ty) concentrations can be utilized as an indication of virgin oil quality or to show if any technological operation has been done on the product. The analysis is therefore useful for classification reasons.
Authors Dobarganes García MC; Rios JJ; Pérez MC
Title Relaciones entre la composición de aceites vegetales y los componentes volátiles producidos durante su termoxidación
Journal Grasas y Aceites, 37, 61-67
Keywords Grasa calentada; Componente volátil;
Abstract En este trabajo se estudian las relaciones existentes entre los componentes volátiles y la composición en ácidos grasos de aceites termoxidados. El análisis del espacio de cabeza muestra grandes diferencias entre los aceites originales no calentados aunque no existen diferencias significativas entre aceites calentados con composición similar en ácidos grasos insaturados. El análisis cualitativo y cuantitativo de los aldehídos mayoritarios procedentes de la descomposición de los hidroperóxidos; confirma la existencia de estas semejanzas en el caso de las grasas termoxidadas, cuando se utiliza una técnica bien normalizada para el aislamiento, concentración y separación de los componentes volátiles. Los resultados indican que a partir del análisis de los aldehídos volátiles, se pueden deducir los ácidos grasos que están sufriendo alteración pero no existe relación entre la cantidad de estos aldehídos y el nivel de degradación. Sin embargo la cantidad de heptanoato y octanoato de metilo, que aumentan desde el comienzo del calentamiento, está directamente relacionada con el grado de termoxidación.
Authors Lanzón A; Albi T; Gracián J
Title Influencia del sistema de extracción en algunos componentes del aceite de oliva. Primeros
Journal Grasas y Aceites, 37, 254-258
Keywords olive oil; composition (variation); Extraction by press; extraction by centrifugation;
Abstract The qualitative and quantitative variations produced in the fatty alcohols; triterpenic alcohols, sterols and triterpenic dialcohols, as a result of the extraction process of the oil have been studied. The processes assayed were the classic one under pressure and the modern one using centrifugation in continuous regime.
Authors Mínguez-Mosquera MI; Garrido FJ
Title Composición y evolución de clorofilas y carotenoides durante el desarrollo y maduración de los frutos del olivo
Journal Grasas y Aceites, 37, 337-342
Keywords carotenoid (pigment); chlorophyll (pigment); colour; green table olives; ripening;
Abstract El estudio de los pigmentos cloroplásticos (clorofilas y carotenoides); en los frutos de las variedades de olivo, Hojiblanca y Manzanilla, ha puesto de manifiesto que la composición cualitativa es idéntica para ambas, y además se mantienen inalterada a lo largo del tiempo. El descenso paulatino y homogéneo de la concentración individual de pigmentos, a medida que avanza la etapa de maduración, es lo que provoca los cambios de color aparente de los frutos. A partir del estado de pintonas, las clorofilas decrecen más rápidamente que los carotenoides, dando paso a otro tipo de compuestos coloreados: las antocianinas
Authors Paganuzzi V
Title Utilidad de la determinación de esteroles y eritrodioles para individualizar el origen de los aceites de oliva vírgenes por métodos quimiométricos
Journal Olivæ, 4, 19-22
Keywords aceites; sterol;
Authors Paganuzzi V
Title Utilitá della determinazione di steroli ed eritrodiolo nella individuazione dell'origine degli oli di oliva vergini mediante metodi chemiometrici
Journal Rivista Italiana delle Sostanze Grasse, 63, 543-549
Keywords olive oil; sterols;
Abstract Vengomo confrontati le composizioni steroliche ed i contenuti in eritrodiolo di oli d'oliva vergini appartenenti alle stesse classi di acidità oleica (inferiore ad 1%; tra 1 e 3 %, oltre 3%) e provenienti da tre diversi Paise (Grecia, Spagna, Tunisia). Ció allo scopo di evidenziare l'utilità di queste determinazionei analitiche nella individuazione dell'origine degli oli di oliva attraverso l'applicazione di metodi chemometrici. A questo fine in componenti dotati del maggior peso de classificazione sono risultati: il campeesterolo, il beta-sitosterolo (ovvero il delta-5-avenaterolo) e l.'eritrodiolo.
Authors Gasparoli A; Fedeli E; Manganiello B
Title Olio vergine di oliva: valutazione dei caratteri roganolettici attraverso tecniche strumentali
Journal Rivista Italiana delle Sostanze Grasse, 63, 571-582
Keywords Aceite de oliva virgen; Atrojado; avinado; Defectos; rancio;
Abstract The authors studied the reply of experimental methods to the evaluation of some defects relevant to the virgin olive oil volatile compounds. By means of head space-GC some components are evidenced that could be connected with ' stantio '; ' avinato ' and ' rancid ' defects this last confirmed by HPLC analysis. The data obtained from the evaluation of some market samples are compared with the sensorial evaluation of a tasters panel.
Authors López Sabater MC; Boatella J; De la Torre Boronat MC
Title Application de l´analyse discriminante à la différenciation d´huiles de différentes variétés
Journal Revue Francaise des CORPS GRASS, 33, 65-67
Keywords variety; olives; discriminant analysis; fatty acids;
Abstract Using discriminant analysis 51 samples of different varieties of olives cultivated in Catalonia (Spain) have been classified. The data used in this analysis are the percentage of 7 fatty acids (7 variables). The most discriminant acids are palmitic; stearic, linoleic and linolenic. These four variables allow to classify correctly 96.1 % of samples.
Authors Gutiérrez González-Quijano R; Gutiérrez Rosales F
Title Método rápido para definir y clasificar el color de los aceites de oliva vírgenes
Journal Grasas y Aceites, 37, 282-284
Keywords aceites; color;
Authors Eddib O; Nickles G
Title Elucidation of Olive Oil Classification by Chemometrics
Journal Analyst, 112, 391-395
Keywords chemometrics; gas chromatography; olive oil;
Abstract Olive oils from Libya; Tunisia and Turkey were analyzed by gas chromatography using capillary columns (Silar 10C - SiO2-Treated surface) with flame-ionization detection. Data on italian olive oils were abstracted from the literature. Both sets were stored and converted into a computer- compatible format. The data were statistically treated by FASCLUS and SCATTER methods contained within the G3D procedures of the SAS computer software package. After suitable processing, canonical variables were statistically established from the data sets for the tested oils, leading to the reliable discrimination of virgin and refined oils. It appears that the G3D system is far better than PLOT representation at discrimination. Five unknowns were examined for their authenticity and were classified as expected. The fatty acid methyl ester database was convenient for chemometric techniques and is suitable for sample identification.
Authors Solinas M
Title Analisi HRGC delle sostanze fenoliche di oli vergini di oliva in relazione al grado di maturazione e alla varietà delle olive
Journal Rivista Italiana delle Sostanze Grasse, 64, 255-262
Keywords HRGC; olive;
Abstract Sono state determinate per GLC su colonna cappillare di SE52 le sostanze fenoliche di oli estratti in microoleificio da olive di diverse varietá; coltivate nella stessa area aziendale.I resultati ottenuti hanno messo in evideza la presenza qualitativamente constance di alcune sostanze caractteristiche, pur con una variabilitá in funzione del facttore varietá delle olive. É stato accertato, altresi, che alcuni rapporti fra taluni costituenti o gruppi di essi si mantengono costanti per amplia intervallo di tempo, indipendentemente dall'evoluzione della maturazione di parametri caratteristici della varietá delle olive.
Authors Solinas M; Marsilio M; Angerosa F
Title Evoluzione di alcuni componenti dell' aroma degli oli vergini di oliva in relazione al grado di maturazione delle olive
Journal Rivista Italiana delle Sostanze Grasse, 64, 475-480
Keywords Aroma; Head space technics; HPLC analysis; olive; olive ripening; virgin olive oils flavor;
Abstract Su campioni di olive della varietá Dritta; raccolte dalla metà di ottobre fino alla fine di gennaio é stato deteminato l'indice di maturazione in funzione del tempo, applicando la metodica dellastazione agronomica di Jaén (Spagna) il rapporto tra gli assorbimenti specttrofotometrici a 665 e 525 nm ed il rapporto acido malico/acido citricoParallelamente sono stati determinati i componenti della frazione volatile degli oli risulta mediante analisi GCL capillare dello 'espacio di testa' e HPLC dei carbonili volatili, degli alcoli volatili e dei compositi insaturi coniugati volatili.I risultati ottenuti hanno messo in evidenza che lo stato di pigmentazione delle olive non puó essere messo in correlazione assoluta, per questa varietá, con la evoluzione di alcuni componenti della frazione volatile ed in particolare con lándamento della 2-esenale, dellaesanale,della epttanale, di alcuni alcoli volatili e del composti insaturi coniugati. Pertanto attraverso la pigmentazione delle olive non é possibile individuare lo stato di maturazione ottimale per ottenere oli di elevata qualitá.
Authors Graciani Constante E
Title Caracterización del aceite de oliva virgen español. II. Su composición en triacilgliceroles por cromatografía líquida de alta eficacia
Journal Grasas y Aceites, 38, 294-302
Keywords high-performance liquid chromatography; Virgin olive oil (composition); analysis of triacylglycerols;
Abstract The triacylglycerol composition of 134 Spanish olive oil samples from two oleicole seasons and 19 oleicoles regions; which can report the national production of this oil, is qualitatively an quantitatively studied. The selectivities of triacylglycerols of Spanish olive oil referred to trioleine, the confidence limits of its quantitative determinations and the limits, maximum and minimum, between the composition in every of them varies for the different tested oils, are established. The distribution functions of the percentages of every main triacylglycerol which are present in Spanish olive oil are reported.
Authors Leardi R; Paganuzzi V
Title Caratterizzazione dell'origine di oli di oliva extravergini mediante metodi chemiometrici applicati alla frazione sterolica
Journal Rivista Italiana delle Sostanze Grasse, 64, 131-136
Keywords extra virgin olive oil; sterols;
Abstract A multivariate analysis performed with different methods on a dataset formed by extra virgin oils imported from Greece; Spain and Tunisia shows that the information brought by the sterolic fraction, together with the acidity, can be used to discriminate quite efficaciously the 3 examined categories (percent of correct predictions higher than 85%). This result does not change even when the multivariate analysis is performed on a quite reduced of variables (5 out of 12).
Authors Firestone D
Title Control of Olive Oil Adulteration and Misbranding in the United States
Journal Rivista Italiana delle Sostanze Grasse, 64, 293-297
Keywords Adulteration; control; olive oil;
Abstract Olive oil imports to the U.S. have been growing over the past several years; from 28,000 metric tons (MT) in 1981 to 44,000 MT in 1985. However, a survey by the Italian Experiment Station for the Fat and Oil Industry in Milan of olive oil products available in 1982 in the U.S. demonstrated that many olive oil products contained undeclared esterified olive oil as well as undeclared olive husk oil and seed oils. These findings led to an FDA regulatory program initiated in 1982 to control olive oil adulteration and mislabeling. Surveys were conducted by FDA in 1983-84 and 1985-86 The 1985-86 survey showed an overall improvement in proper labeling of various olive oil products. Tighter control by exporting countries and continued surveillance in the U.S. are required to eliminate adulteration of olive oil.
Authors Kapoulas VM; Andrikopoulos NK
Title Detection of Virgin Olive Oil Adulteration with Refined Oils by Second-Derivative
Journal Food Chemistry, 23, 183-192
Keywords refined oils; spectrophotometry; Virgin olive oil;
Abstract Weak adsorption maxima of conjugated tetranoic systems (285-315 nm) can be quantitated by second-derivative spectrophotometry. The distance of two consecutive extremes (maximum-minimum) of the second-derivative reflection at 315 nm; measured in units of absorptivity (DK315) shows the most characteristic differences between virgin olive oil and refined olive, olive kernel and seed oils. The ranges of DK3151% values were found to be 0.008--0.015 and 0.010--0.030 for virgin olive oils of the last and older crops, respectively, whereas DK33151% values of refined olive and olive kernel oils exceed 0.450 and 0.990, respectively. It is demonstrated that 5% adulteration of virgin olive oil by refined oils may be detected effectively by this technique.
Authors Tsimidou M; Macrae R; Wilson I
Title Authentication of Virgin Olive Oils Using Principal Component Analysis of Triglyceride and Fatty Acid Profiles: Part 1-Classification of Greek Olive Oils
Journal Food Chemistry, 44, 227-239
Keywords fatty acid; Greek olive oil; statistics; triglyceride;
Abstract A method is described for the chromatographic separation and quantitative determination of phenolic compounds in virgin olive by high-performnce liquid chromatography (HPLC) using gradient elution. For the determination of individual compounds molar absorptivities at 280nm are calculated. A technique based on the use of four external standards (tyrosol; vanillic acid, syringic acid, o-coumaric acid) is applied in order to minimize errors due to different lmax and e280. The method was applied successfully to olive oil samples.
Authors Casadei E
Title Primi risultati sulla ricerca di adulterazione degli oli di oliva per aggiunta di olio di nocciole o oli esterificati mediante analisi dei trigliceridi
Journal Rivista Italiana delle Sostanze Grasse, 64, 373-376
Keywords Adulterations of olive oil;
Abstract The triglycerides of refined olive and hazel-nut oil has been studied by HPLC. Four significant indices; obtained by relation of poly-unsaturated triglycerides, were fixed to detect adulterated and misbranded olive oil products with hazel-nut oil, in minimum quantity of 25%. This method is appropriate even to detect adulterated olive oil with esterified oil.
Authors Mariani C; Fedeli E; Morchio G
Title Sul contenuto di eritrodiolo assoluto quale possibilità di individuare il sansa nell'olio di oliva
Journal Rivista Italiana delle Sostanze Grasse, 64, 359-363
Keywords detect olive husk oil; olive oil;
Abstract The official method for erythrodiol determination is based on the relative per cent of the same in comparison with sterols content. This per cent is not sufficient to suitably determine the different quantity of terpenic dialcohols really present in the various kinds of olive oil in that their sterols content; acting as a term of comparison, is different.
Authors Mariani C
Title I problemi del controllo di qualitá
Journal Rivista Italiana delle Sostanze Grasse, 64, 325-333
Keywords The problems of quality control;
Abstract The present work examines some aspects relevant to fatty matter analysis. The problems connected with the matrix characterization and the fast and simplified methods recently published are examined in detail. The possibility of establishing on operational sequentiality based on the example of other analytical sectors is shown.
Authors Derde MP; Buydens L; Guns C; Massart DL
Title Comparison of Rule-Building Expert Systems with Pattern Recognition for the Classification of Analytical Data
Journal Analytical Chemistry, 59, 1868-1871
Keywords Building; expert systems; Pattern recognition; classification;
Abstract Two expert systems of the rule-building type; TIMN and EX - TRAN, are compared with pattern recognition methods for the classification of olive oils of different origins. Both expert systems are more user-friendly than the pattern recognition programs and TIMM yields slightly better results than nearest neighbors classifiers and linear discriminant analysis.
Authors Solinas M; Angerosa F; Cucurachi A
Title Connessione tra prodotti di neoformazione ossidativa delle sostanze grasse e insorgenza del difetto di ranciditá all'esame organolettico. Nota 2. Determinazione quantitativa
Journal Rivista Italiana delle Sostanze Grasse, 64, 137-145
Keywords oxidation; Rancidity;
Abstract É stata effettuata de la determinazione quantitativa dei composti volatili responsabili della ranciditá degli oli di oliva; rilevabile mediante esame oranoleptico. A tal fine la frazione volatile esttrata per strippagio con azoto a 37ºC é stata analizzata per GLC capillare e per HPLC dei fenildrazoni dei carbonili e dei composti insaturi coniugati rivelati a229nm, In parallelo è stato effettuato l'esame organolettico del campioni di olio da un Panel di asseggiatori. I resultati della ricerca hannomesso in evidenza che i composti carbonilici più direttemente correlabili con la ranciditá sono: la 2-pentenale,l'esanale, la 2-eptenale, l'eptanale, la 2-ottenale,l'ottanae e la nonanale. Di essi,´iú indicativi del processo sono la 2-pentenale e la 2-eptenale; la sglia di apparizione della ranciditá coincide con la presenza nell'olio di 0,5 ppm della prima e di 1,5 ppm della seconda.
Authors Aparicio López R; Albi T; Lanzón A; Navas MA
Journal Grasas y Aceites, 38, 9-14
Keywords artificial intelligence; expert system; Multivariant analysis; olive oil identification;
Abstract The SEXIA -an Expert System to the olive oils identification according to the olive variety or/and the Denomination of Origin- is been currently developed at the Instituto de la Grasa. This paper is intended to propose a new methodological approach to distinguish among olive oils of several Spanish olive grove zones with the minimum of chemical parameters. The paper describes and illustrates in detail; for instance, the percentages of correct classifications, the chemical parameters of the olive oil analyzed and their contributions to the discriminant analysis, the mistakes on the identifications, etc. All of them are a part of the Data Base of SEXIA. Finally, promising directions for future research are presented in the conclusions.
Authors Aparicio López R
Title Characterization of foods by inexact rules: the SEXIA expert system
Journal Journal of Chemometrics, 3, 175-192
Keywords certainty factors; evidence; expert systems; plausibility;
Abstract SEXIA is an expert system that uses a new methodological approach to identify foods; particularly olive oils according to varieties, olive zones and denominations of origin. The methodological approach provides identification tools, associating a confidence degree or a belief interval to the final hypotheses. The certainty factor and the Dempster-Shaffer theory, with some modifications, have been implemented in SEXIA. The computer can work with 50 chemical parameters whose data have previously been acquired by the food analyst via a dialogue in the Spanish language. The system has been verified with 144 olive oil samples. In this paper some results obtained for distinguishing the Arbequina variety from other varieties using SEXIA and the BMDP stepwise discriminant analysis program are presented. Finally, promising directions for future research are suggested.
Authors Di Giovacchino L; Mascolo A
Title Incidenza delle tecniche operative nell,estrazione dell,olio dalle olive con il sistema continuo
Journal Rivista Italiana delle Sostanze Grasse, 65, 283-289
Keywords expert system; olive oil;
Abstract During the olive harvests of 1983-84-85 oil extraction tests were made using the percolation-centrifugation system. The duration of the kneading process and the oil/solids ratio of the olive paste were varied and some additives were mixed with the paste to help the extraction process. The results obtained show that the duration of the kneading phase affects the yield of the extraction process especially when the olive paste is 'difficult '; in which case it becomes necessary to prolong the operation time. The results obtained by varying the oil / solids ratio of olive paste show that with 'easy' olives it's possible to extract oil from pitted olive paste (higher oil / solids ratio), while with ' difficult ' olives higher extraction yields are obtainable when the ratio is lowered by adding virgin olive husk. The results obtained processing olive paste treated with additives show that enzymes only aid in the extraction of olive oil even when the dosage is low.
Authors Dobarganes García MC; Pérez Camino MC
Title Fatty acid composition: a useful tool for the determination of alteration level in heated fats
Journal Revue Francaise des CORPS GRASS, 2, 67-70
Keywords fatty acid; Heated fat;
Abstract In this paper; 3 different methods to define both the percentage of non-altered methyl ester and the loss of different fatty acid during heating are described. The results of the application of these methods to palm, olive, sunflower and soybean oils with different thermoxidative levels are discussed.
Authors Fellat-Zarrouck K; Bouteiller JC; Maurin R
Title Recherche par CLHP de quelques adultérations de l´huile d´olive par des huiles de graines
Journal Revue Francaise des CORPS GRASS, 33, 383-385
Keywords Adultération d'huile d'olive;
Abstract HPLC quantitative analysis of triglycerides in some seed oils allows the determination of polyunsatured samples; soya and sunflower oils contains an important percentage of trilinoleoylglycerol (23 to 43%) soya oil contains also dilinoleoyllinolenoyl - rac - glycerol. Pure olive oil is free from these polyunsaturated triglycerides. Thus; HPLC determination of polyunsaturated triglycerides in olive oil is an interesting method to show up adulteration by these seed oils; the accuracy is not less than 1%.
Authors Solinas M; Angerosa F; Marsilio M
Title Indagine su alcuni componenti dell' aroma degli oli vergini di oliva in relazione alla varietà delle olive.
Journal Rivista Italiana delle Sostanze Grasse, 65, 361-368
Keywords Head space technics; volatile components; HPLC analysis; Olive variety; Aroma; olive;
Abstract Su campioni di oli estratti da olive di dieci varietá locali ed importate (Dritta; Nebbio, Castiglionese, Carboncella, Leccino, Caroleo, Grossa di Cassano, Frantoio, Maurino), coltivate in ambientepedoclimatico omogeneo e campionate negli stessi periodi di tempo, sono state condotteanalisi HPLC dei carbonili volatili, degli alcoli volatili, dei composti insaturi coniugati volatili. I risultati ottenuti hanno messo in evidenza che é possibile individuare nellánalisi dello spazio di testa picchi esclusivi ed indicativi della provenienza e la 2-esenale, di per sé ed in rapporto alla frazione aldeica complessiva, è una caratteristica varietale. Fra gli alcoli volatili ne sono stati individuati alcuni (probabilmente propanoli, butanoli,amilici,2-esenolo,esanolo,eptanolo) presenti in percentuali correlabili con la varietà delle olive originarie. Infine, L'analisi HPLC dei composti insaturi coniugati evidenzia un gruppo di pichi che presentano un contenuto nell'olio assoluto e relativo alla 2-esenale, chiaramente dipendente dalla varietà.
Authors Firestone D; Carson KL; Reina RJ
Title Update on Control of Olive Oil Adulteration and Misbranding in the United States
Journal Journal of the American Oil Chemists Society, 65, 788-792
Keywords control; olive oil; Adulteration;
Abstract The Food and Drug Administration has carried out a regulatory program since 1982 to control olive oil adulteration and mislabeling in the U.S. Analysis of imported and domestically packaged olive oil products and inspection of domestic packers have significantly reduced the presence of undeclared esterified olive oil in olive oil products. Undeclared esterified olive oil was present in 13% of olive oils examined in a 1985-86 survey; compared to 65% in a 1983-84 survey. Undeclared olive pomace oil and seed oils continue to require surveillance in a continuing effort to eliminate olive oil adulteration.
Authors Mattei A; Stella C; Osti M
Title Olio extra vergini di oliva e componenti polari minori: influenza dei sistemi e delle condizioni di estrazione
Journal Rivista Italiana delle Sostanze Grasse, 65, 575-579
Keywords Extra virgin olive oil and minor polar components;
Abstract The A.A. began a research regarding minor polar components of extra virgin olive oil. The influence of extraction plants over the content and distribution of CMP was analyzed. The variation of the same components during the storage was investigated too. It appears quite clear that the change in the CMP content is related to hydrolytic reaction that continue during the oil storage.
Authors Gutierrez F; Albi MA; Palma R; Rios JJ; Olías JM
Title Bitter Taste of Virgin Olive Oil: Correlation of Sensory Evaluation and Instrumental HPLC Analysis
Journal Journal of Food Science, 54, 68-70
Keywords bitter components; HPLC analysis; sensory evaluation; bitter taste; Virgin olive oil; correlation; analysis;
Abstract A method for the extraction by C18 columns and HPLC analysis of bitter components of virgin olive oils was developed. Factorial design showed the suitability of using two columns and three HPLC analyses per sample. An equation obtained by multiple regression analysis; related bitterness with the area of peaks, which explained 92% or variance.
Authors Gutiérrez Rosales F
Title Determinación de la estabilidad oxidativa de aceites de oliva vírgenes: Comparación entre el método del Oxígeno Activo (A.O.M.) y el método Rancimat
Journal Grasas y Aceites, 40, 1-5
Keywords active oxygen method; method (comparison); Rancimat method; stability; virgin olive oil;
Abstract Se hace un estudio comparativo; sobre 26 muestras de aceites de oliva vírgenes, entre el método normalizado del Oxigeno Activo (AOM) y el método Rancimat, basado en la determinación conductimétrica de los productos volátiles de degradación. Los resultados obtenidos muestran que hay una correlación muy buena entre ambos métodos. El método Rancimat ofrece una alternativa real para la determinación de las estabilidades oxidativas debido al apreciable ahorro de tiempo al trabajar en continuo.
Authors Armanino C; Leardi R; Lanteri S
Title Chemometric Analysis of Tuscan Olive Oils
Journal Chemometrics and Intelligent Laboratory Systems, 5, 343-354
Abstract The chemical information (fatty acids; sterols, triterpenic alcohols) on 120 olive oil samples from Tuscany, Italy, collected in 88 different areas of production, was evaluated by display methods and cluster analysis. Inside this small region of varied orography, four groups of similar samples were detected and some relationships with the geographic profile were revealed by using a CAD package to produce effective geographical representations of variables, eigenvectors and clusters.
Authors Morchio G; Di Bello A; Mariani C; Fedeli E
Title Individuazione di particolari oli rettificati in oil vergini di oliva
Journal Rivista Italiana delle Sostanze Grasse, 66, 251-257
Abstract Up until today analysis by UV specific extinction values has been successfully used to differentiate between refined and blended olive oils from virgin olive oils. However; lately appeared on the national market imported refined oils whose characteristics of negligible UV absorption have values very similar to those of virgin oils. With the present works we are putting forward two alternative methods to spectrofotometric measurements in order to identify the refined oils with a low UV absorption blended (5-10%) with virgin oils. Its sensitivity is believed to be sufficient in the commercial sector to act as a deterrent to the diffusion of the above blends.
Authors Mínguez-Mosquera MI; Garrido FJ
Title Chlorophyll and Carotenoid Presence in Olive Fruit (Olea europaea)
Journal Journal of Agricultural and Food Chemistry, 37, 1-7
Keywords chlorophyll; carotenoid; olive; Olea europaea;
Abstract The high lipids content of olive fruits infers an interference in chlorophyll isolation and identification. The use of phase separation between hexane and N; N-dimethylformamide permits obtaining a chloroplast pigment extract free of fatty matter. In fact, n,N-dimethylformamide has been proven to be a good solvent for the extraction of these pigments as it does not give rise to alteration in the chlorophyll molecule. The study of chloroplast pigments (chlorophylls, carotenoids) in fruits of Hojiblanca and Manzanilla olive varieties has shown that the qualitative composition is the same for both and does not change with maturation time. During the growth and development stages, a gradual and homogeneous decrease is observed in the individual concentration of both chlorophylls and carotenoids. In all phases, Hojiblanca variety has greater wealth of pigment than Manzanilla.
Authors Lanzón A; Cert A; Albi T
Title Detección de la presencia de aceite de oliva refinado en el aceite de oliva virgen.
Journal Grasas y Aceites, 40, 385-388
Keywords refined olive oil; stigmasta-3;5-diene; Virgin olive oil;
Abstract In refined olive oils; significant amount (3-100 ppm) of stigmasta-3,5-diene has been detected. On the other hand, in virgin olive oils, the quantity of this compound is negligible. Therefore, a analytical method based on the stigmasta-3,5-diene determination has been developed. This procedure permits, in the most unfavoured case, the detection of minor amounts (1% or less) of refined oil in virgin olive oil.
Authors Cortesi N; Provellini P; Fedeli E
Title I Triglycerides of natural oils. Note1
Journal Rivista Italiana delle Sostanze Grasse, 67, 69-73
Keywords triglycerides; natural oils;
Abstract Triglycerides are among the most important constituents of fats and oils. By utilizing a computer program the triglycerides composition according to the 1;3-random 2-random distribution or full random distribution of an oil or fat can be calculated starting from the fatty acids composition as determined by GLC. The calculated data are compared to those experimentally produced by utilizing a HPLC method; the comparison is done on ECN classes or on individual triglyceride species. The comparison consents to evaluate deviations from the accepted distribution rules and the existence of mixtures, in a given oil, of oil of different botanical origins. The methodology is very useful to discover the presence of foreign oils in olive oil as well as to show the presence of esterified oils.
Authors Nergiz C; Ünal K
Title The Effect of Extraction systems on Triterpene Alcohols and Squalene Content of Virgin Olive Oil
Journal Grasas y Aceites, 41, 117-121
Keywords extraction system; Squalene (content in); stability; Triterpene alcohol (content in); Virgin olive oil;
Abstract Influencias de los sistemas de extracción sobre el contenido en alcoholes triterpénicos y escualeno de oliva virgen.
Authors Mesa JAG; Linares P; Luque de Castro MD; Valcárcel M
Title Direct automatic determination of polyphenols in olive oils in the aqueous phase of a flow-injection liquid-liquid extraction system without phase separation
Journal Analytica Chimica Acta, 235, 441-444
Keywords polyphenols; olive oil; extraction;
Abstract A method the determination of polyphenols in olive in which the analytes are extracted the aqueous phase by a liquid-liquid extraction system based on the use of a flow direction is proposed. Nome of typical units for this continuous separation technique are required by the proposed configuration. The analytes can be determined in the range over which polyphenols normally occur in these samples (100-900 mg ml-1) with better precision (2.8-4.0% vs. 6%) and sampling frequency (2.8 h-1 vs. 0.5 h-1) and sample (>1g vs. 30g) and reagent consumption than by the conventional method.
Authors Passaloglou-Emmanouilidou S
Title A comparative study of UV spectrophotometric methods for detection of olive oil adulteration by refined oils
Journal Zeitschrift für Lebensmittel Untersuchung und-Forschung, 191, 132-134
Keywords olive; Adulteration;
Abstract UV spectrophotometric measurements on hundreds of virgin olive oils and refined vegetable oils have shown that a previous method for evaluating the absorption maxima at 315 nm by calculation an Rs value (ratio of slopes of absorption curve in both sides of 315 nm) may lead to false conclusions concerning possible adulteration of virgin olive oils by refined olive; olive residue or seed oils. It was found that deltaK3154% values, obtained directly from the UV spectra, are much more reliable estimates of conjugated tetraene absorption a 315 nm, without affecting the sensitivity of the method.
Authors Lentza-Rizos C; Avramides EJ
Title Determination of Residues of Fenthion and its Oxidative Metabolites in Olive Oil
Journal Analyst, 115, 1037-1040
Keywords fenthion residue determination; olive oil; organophosphorus pesticide; oxidized metabolite;
Abstract A method is described for the determination of residues of fenthion and its oxidative metabolites in olive oil. After extraction; the residues are oxidized with potassium permanganate to fenthion sulphone and fenthion oxon sulphone and determined by gas-liquid chromatography using nitrogen - phosphorus detection. The method is both simple and sensitive.
Authors Mariani C; Venturini S; Fedeli E
Title Sulla presenza di prodotti alogenati volatili negli oli vergini di oliva
Journal Rivista Italiana delle Sostanze Grasse, 67, 239-244
Keywords Virgin olive oil; volatile halogenated products;
Abstract The presence in some virgin olive oils of chlorinated solvents as trichloroethylene is widely accepted; nevertheless other volatile halogenated compounds as chloroform; bromodichloromethane, dibromochloromethane and tribromomethane may be present. The presence of these compounds in waters, in particular in the ones submitted to potabilisation by chlorination, is widely documented; it is possible that these compounds are transferred from the water to the oil during processing operations. The Authors set up the operative conditions for the determination of these products in the oils in presence of trichloroethylene and tetrachloroethylene, determination not possible by the official methods now available.
Authors Cimato A; Sani G; Mattei A; Osti M
Title Cultivars and environment as regulating factors in polyphenol and tocopherol contents of the Tuscan Oil
Journal Acta Horticulturae, 286, 457-460
Abstract Tuscan olive oils contain different levels of polyphenols and tocopherols depending on the degree of fruit ripeness; the cultivar and the area of origin. From 3 November 1988 to 18 December 1989, samples of olives of the cultivars 'Frantoio', Leccino' and ' Coratina' were harvested in two climatic areas of Tuscany (Grosseto and Florence). During the first period of harvesting polyphenol and tocopherol levels were higher, irrespective of environment and cultivar, and gradually declined as the fruits ripened. More complex variations were seen when the polyphenol and tocopherol values were related to production area or cultivar.
Authors Frega N; Bocci F; Lercker G
Title The HRGC determination of triglycerides
Journal Italian Journal of Food Science, 4, 257-264
Keywords triglycerides; HRGC;
Abstract Triglyceride determinations are presently performed using gas chromatographic (HRGC) and liquid chromatographic (HPLC) separations based both on the total of carbon atoms and on the degree of unsaturation of their corresponding fatty acids. The HRGC ' TAP ' column (Chrompak) can separate triglycerides from natural sources. The application of this technique to the total lipid analysis of a virgin olive oil gave good repeatability. The coefficient of percentage variation was between 2-7 % for the quantitative evaluation of the main HRGC peaks (1-42 % of relative amount). The presence of trilinolein in all samples of virgin olive oils was below of 0.3 %; while in the seed oils a high amount of this triglyceride was present. The power of separation characteristic of the TAP column was utilized for the triglyceride determination of several natural oils and lipids. The results relative to some different virgin olive oils show a rather constant quantitative composition, characteristic of the lipid substrate.
Authors Cruz Madueño E
Title El orujo de aceituna
Journal Alimentación; Equipos y Tecnología, 1-27
Keywords Pomace oil;
Abstract Se estudia la composición química del orujo graso de aceituna; así como la del aceite extraído, comparándose,en relación con sus componentes mayoritarios y otros de naturaleza más especifica, con el aceite de oliva. Por otro lado se hace una breve revisión de los métodos analíticos que actualmente, se llevan a cabo en la práctica para su valoración, y se destaca la necesidad de una normativa oficial que complemente a las ya existente.
Authors Grob K; Lanfranchi M; Mariani C
Title Evaluation of Olive Oils Through the Fatty Alcohols, the Sterols and Their Esters by Coupled LC-GC
Journal Journal of the American Oil Chemists Society, 67, 626-634
Keywords Coupled LC-GC; minor components of olive oil; olive oil; sterol fractions; wax esters;
Abstract The analysis of the fatty alcohols; the wax esters, the free and the esterified sterols, as well as that of minor components provides a wealth of information about the quality of an oil or fat, its pretreatment and admixture with other oils. Some results obtained by an easy, nearly fully automated method are shown for olive oils. More specific information is obtained than by the previous saponification methods.
Authors Mínguez-Mosquera MI; Gandul Rojas B; Garrido Fernández J; Gallardo-Guerrero ML
Title Pigments Present in Virgin Olive Oil
Journal Journal of the American Oil Chemists Society, 67, 192-196
Keywords pigments; Virgin olive oil;
Abstract The qualitative and quantitative control of pigments in ripe olives and in extracted virgin olive oil has increased our knowledge of the influence on these compounds in the areas of ripening of the fruit; storage time in the factory and the oil extraction process. as the harvesting time of the fruits increases, pigment content decreases. During storage, the presence of lipoxigenase has been detected, as well as a considerable decrease in chlorophylls and a small decrease in carotenoids, During the extraction process, the chlorophyllic fraction is destroyed in the greater part, and although the carotenoid fraction is also affected, its concentration increases in the oil with respect to that in the fresh fruit. In the pigment degradation, in addition to the acid-catalyzed reaction, the presence of lipoxigenase suggests a role for this enzyme.
Authors Marini D; Grassi L; Balestrieri F; Pascucci E
Title Analisi spettrofotofluorimetrica dell'olio di oliva. Possibilitá di applicazione
Journal Rivista Italiana delle Sostanze Grasse, 67, 95-99
Abstract Commercial 'olive oils' consist of mixtures of virgin and refined olive oil but the olive oil amount is not fixed. To this purpose; the authors have verified the possibility to use the spectrophotofluorimetry for the acknowledgment and assay of virgin olive oil in mixture with refined oil.
Authors Montaño A; Sánchez AH; Rejano L
Title Rapid quantitative analysis of headspace components of green olive brine
Journal Journal of Chromatography, 521, 153-157
Keywords analysis; green olive brine; headspace; headspace components; olive;
Abstract In order to study the complex biochemical transformations which take place during the controlled fermentation of vegetables; it is important to have analytical methods available that allow the determination of vegetables, it is important to have analytical methods available that allow the determination of the main compounds involved. The sugars and the majority of organic acids (fructose, glucose, mannitol, sucrose, lactic acid, acetic acid, malicacid) can be satisfactorily determined by high-performance liquid chromatography. Ethanol, another important component, can also be determined by this technique  but, owing to its volatily, gas chromatography (GC), and particularly the headspace technique (HSGC), is more appropriate . This paper describes a simple, rapid method for the simultaneous determination of ethanol and other volatile components in brines of fermented vegetables by HSGC: The study was centered on green table olives,which, together with cucumbers, cabbages and peppers, account for the largest of vegetables and fruits commercially brined and fermented in the West .
Authors Mínguez-Mosquera MI; Garrido FJ; Gandul Rojas B
Title Quantification of Pigments in Fermented Manzanilla and Hojiblanca Olives
Journal Journal of Agricultural and Food Chemistry, 38, 1662-1666
Keywords pigments; Hojiblanca; olives;
Abstract The color change observed in the fruits of the table olive during the process of lactic fermentation is confirmed as due exclusively to the structural modification of pigments; caused by action of the enzyme chlorophylls and the progressive acidity of the medium. The qualitative and quantitative knowledge of the pigments present in the fermented fruit has made the perfecting of a rapid spectrod-photometric method for the evaluation of the principal fractions of pigment possible. From the absorption spectrum of the crude extract, the different fractions are calculate at the following wavelengths: total pigments at 406nm, carotenoids at 476nm, and chlorophyll derivates a 668nm. There is a good correlation between pigment content and fruit color.
Authors Todeschini R; Velata A; Cozzoli O; Fedeli E; Daghetta A
Title Applicazioni chemiometriche allo studio delle correlazioni tra valutazioni sensoriali e dati chimico-fisici di oli exta vergini di oliva
Journal Rivista Italiana delle Sostanze Grasse, 67, 553-558
Keywords valutazione sensoriali di extra vergini di oliva;
Abstract L'insieme multivariato di dati chimico-fisici e sensoriali ottenuto dall'analisi di 74 oli extra vergini di oliva èstato studiato con alcune tecniche chemometriche allo scopo di ricercare informazioni utili alla preveditá del giudizio sensoriale in funzione dei risultati analitici. Le diverse prove effetuate hanno messo in luce difficoltá nella completa correlazione dei due tipi di variabili; essenzialmente attibuibile ad effetti di non linearitá. Sulla base di questi risultati appare rilevante uno sviluppo di questo studio utilizzando anche tecniche non linare.
Authors Guth H; Grosch W
Title A Comparative Study of the Potent Odorants of Different Virgin Olive Oils
Journal Fatty Science Technology, 93, 335-339
Keywords Virgin olive oil; flavour; odour notes; odorants;
Abstract The flavour of virgin olive oil was investigated by means of an aroma extract dilution analysis. A comparative study of four oil samples differing in the flavour; indicated that the following odorants were mainly responsible for the odour notes given in brackets: (Z) -3-hexenol, hexanal, (E)-2-hexenal and (Z)- 3- hexenal (green), ethyl 2- methylbutyrate, (Z)- 3-hexenyl acetate and ethyl cyclohexanoate (fruity), (E,E)-2,4-decadienal, (E)- and (Z) -2-nonenal (fatty) and 4-methoxy-2-methyl-2-butanethiol (black currant-like).
Authors Alberghina GCaruso L; Fisichella S; Musumarra G
Title Geographical Classification of Sicilian Olive Oils in Terms of Sterols and Fatty Acids Content
Journal Journal of the Science of Food and Agriculture, 56, 445-455
Keywords areas of production; classification; Etna olive oils; fatty acids; Principal components analysis; Sicilian olive oils; sterols;
Abstract The sterol and fatty acids contents of 22 extra virgin olive oil samples produced in the Etna area and in other areas of Sicily were determined. Principal component analysis (PCA) of these data `provided a'scores' plot were samples produced in the Etna area were clearly grouped and unknown samples could be classified according to their geographical origin. This classification was confirmed by the residual standard deviation values of all samples fitted into a disjoint principal components model derived from Etna oils only. The above results suggest that the DOC (denominazione di origine controllata) origin mark for Etna extra virgin olive oils can be attributed on the basis of their sterols and fatty acids contents by means of PCA.
Authors Mariani C; Bondioli P; Venturini S; Fedeli E
Title Sulla formazione di acidi grassi trans nel processo di raffinazione dell´olio di oliva lampante
Journal Rivista Italiana delle Sostanze Grasse, 68, 455-459
Keywords Fatty Acids Lampant Olive Oil; trans;
Abstract The use of strong operating conditions during refining process; with particular reference to the bleaching and deodorizing steps may result in great changes on fatty matter structure. One of these effects is trans fatty acids formation. In this work results of a systematic research about the formation of said compounds in bleaching and deodorizing lampante olive oil are shown. The obtained data indicate that the effects of these operations on trans fatty acids formation, if carried out in strong operating conditions, are evident and easily detectable.
Authors Fiorino P
Title Maduración de las Aceitunas y Variaciones de algunos Componentes del Aceite
Journal Olivæ, 35, 25-33
Keywords maduración de las aceitunas;
Authors Aparicio López R; Ferreiro L; Rodríguez JL
Title Caracterización de alimentos combinando reglas de decisión relacionales y lineales. Una aplicación al aceite de oliva virgen de Málaga
Journal Grasas y Aceites, 42, 132-142
Keywords Virgin olive oil; food (caracterization); Málaga; Rule of lineal decision; Rule of relacional decision;
Abstract Los componentes químicos de un alimento cuantificados por cromatografía gaseosa; pueden ser usados para construir reglas de decisión relacionales y lineales que, combinadas mediante algoritmos matemáticos, podrían permitir su caracterización.
Authors Menichini E; Di Domenico A; Bonanni L
Title Reliability assessment of a gas chromatographic method for polycyclic hydrocarbons in olive oil
Journal Journal of Chromatography, 555, 211-220
Keywords gas chromatographic method; hydrocarbons; olive oil;
Abstract A quality control test was developed a gas chromatographic method to determine polycyclic aromatic hydrocarbons in olive oil. Fifteen oil specimens were fortified with eight three-To six-ring polycyclic aromatic hydrocarbons at levels of between 3.0 (approximate detection limit) and 360 mg/kg.Three sets of five equally fortified specimens were obtained and assayed at random by there operators. For each fortification level; the means of recovery yield were in the range 56-107%, and were independent of data associated with both the fortification level at the detection limit and a deviant polycyclic aromatic hydrocarbon term (benzo[ghi]perylene), an overall mean accuracy of 96% and a precision of 7% were achieved.
Authors Gonçalves M; Vasconcelos AMP; Gomes de Azevedo EJS; Chaves das Neves HJ; Nunes da Ponte M
Title On the Application of Supercritical Fluid Extraction to the Deacidification of Olive Oils
Journal Journal of the American Oil Chemists Society, 68, 474-480
Keywords deacidification; husk oil; olive oil; supercritical carbon dioxide;
Abstract A recent suggestion on the applicability of supercritical fluid extraction to the deacidification of olive oils of high acid content was based on solubility data in clear disagreement with the results of other authors. In this work; we measured the solubilities of substances chosen for their importance in that extraction process, namely pure glycerol trioleate, the most abundant triglyceride in olive oil, and of a husk oil with acid content. Our results agree well with some of the previous reports on this subject. These seem to be a trustworthy data base, but more results are needed for a definite conclusion about the technical feasibility of the process.
Authors Mínguez-Mosquera MI; Gandul Rojas B; Montaño-Asquerino A; Garrido Fernández J
Title Determination of chlorophylls and carotenoids by high-performance liquid chromatography during olive lactic fermentation
Journal Journal of Chromatography, 585, 259-266
Keywords chlorophyll; carotenoid; high-performance liquid chromatography; olive; lactic fermentation;
Abstract Eighteen pigments; including chlorophylls, carotenoids and their degradation products, were separated by reserved-phase ion-pair high- performance liquid chromatography during the lactic fermentation and later preservation phase of green table olives. The method consists of an elution gradient using two solvents: water-ion-pair reagent-methanol (1:1:8, v/v/v) and methanol- acetone (1:1 v/v). Absorbance detection of all the pigments is carried out spectrophotometrically at 430nm. Pigment concentrations are calculated from an extension of Beers law. This procedure is compared with the external standard method. The analysis of variance showed no significant differences between the results given by the two methods.
Authors Frega N; Bocci F; Lercker G
Title Composizione lipidica della drupa di olivo di due cultivars della zona del Chianti in funzione della maturazione. Nota I:trigliceridi ed acidi grassi
Journal Rivista Italiana delle Sostanze Grasse, 68, 69-74
Keywords Fatty acid; lipids; olive oil;
Abstract This paper is the first of a wide study on the individuation of the parameters which are enable to characterize the extra virgin olive oils; also with the aim to recognize the optimum period of gathering of fruits. The triglyceride and fatty acid compositions of the oils extracted from the different parts of the drupe and the corresponding oils obtained by pressure technology during the ripening from two cultivars (Frantoio and Leccino) of Chiantis' country,’ were studied by capillary gas chromatography. The triglyceride composition of the kernel oil results quite different from those of the oils extracted by solvent and by pressure technology. In all samples the trilinolein (LLL) content is bellow of 0.2 % of total triglycerides. No substantial quantitative variations are showed during the ripening in both the pressure technology and solvent extraction oils. Light modifications are observed on the amounts of the main fatty acids of the pulp oils (from solvent extraction and pressure technology generated) against the rather constant amount of the cis-vaccenic acid in all oils.
Authors Di Giovacchino L
Title L' estrazione dell'olio con la centrifugazione diretta delle paste di olive Nota I: Influenza della gramolazione
Journal Rivista Italiana delle Sostanze Grasse, 68, 413-420
Keywords extraction; olive oil; olive paste (centrifugation);
Abstract A study was undertaken to ascertain the effect that the kneading operation has on oil yields and on the properties of oils and by- products obtained by direct centrifugation of olive pastes. The results obtained have helped establish that an increase of the duration and temperature of the kneading phase determines higher extraction yields; specially in the case of ' difficult ' olives. These positive results have been confirmed by the lower oil residue present in the olive husks and in vegetable waters. The variation of the kneading time and temperature determine, instead, a lower influence on the qualitative characteristics of olive oils obtained which show, however, significant differences only on the phenol substances content. The same oils, finally, don' t show significant differences in resistance to oxidation during conservation.
Authors Albi MA; Gutiérrez F
Title Study of the Precision of an Analytical Taste Panel for Sensory Evaluation of Virgin Olive Oil. Establishment of Criteria for the Elimination of Abnormal Results
Journal Journal of the Science of Food and Agriculture, 54, 255-267
Keywords panel errors; precision; sensory evaluation; Virgin olive oil;
Abstract The errors of an analytical taste panel used in the sensory evaluation of virgin olive oil have been determined; after eliminating outlying taster, in order to determine the panel's precision. The confidence limits of the mean have been calculated for defined work schemes. The limits obtained +0'4 to +0'5 employing a scale of 9 points and duplicate determinations,give sufficient precision. A methods is proposed for the determination of criteria to allow the routine elimination of outlying results, either from a replicate or from the mean of each taster.
Authors Papadopoulos G; Boskou D
Title Antioxidant Effect of Natural Phenols on Olive Oil
Journal Journal of the American Oil Chemists Society, 68, 669-671
Keywords antioxidant activity; olive oil; phenols; polar fraction; protection factor;
Abstract The total polar fraction and individual phenols present in virgin olive oil were tested for their antioxidant effect in refined olive oil. Hydroxytyrosol and caffeic acid showed protection factors greater than BHT. Protocatechuic and syringic acid were also found to have antioxidant activity. Tyrosol; p-hydroxyphenylacetic acid, o-coumaric acid, p-coumaric acid, p-hydroxybenzoic acid and vanillic acid had very little or no effect, and their contribution to the stability of the oil is negligible.
Authors García JM; Streif J
Title The Effect of Controlled Atmosphere Storage on Fruit and Oil Quality of Gordal Olives
Journal Gartenbauwissenschaft, 56, 233-238
Keywords storage; oil quality; olives;
Authors Sanchez Saez JJ; Garraleta Herce MD; Balea Otero T
Title Identification of cinnamic acid ethyl ester and 4-vinylphenol in off-flavour olive oils
Journal Analytica Chimica Acta, 247, 295-297
Keywords gas chromatography; mass spectrometry; olive oil;
Abstract Some alkylphenols have previously been identified in concentrates steam distillates of olives oils gas chromatography- mass spectrometry. In such analyses of unacceptable olive oils. the compounds found included cinnamic acid ethyl ester; 4-vinyphenol and styrene. 4-Vinylphenol is probably derived from P-coumaric acid decarboxylation during storage of olives. Other compounds identified from their mass spectra were guaiacol and dimethoxybenze.
Authors Aparicio López R; Sánchez-Navarro M; Ferreiro MS
Title Definite influence of the extraction methods on the chemical composition of virgin olive oil
Journal Grasas y Aceites, 42, 356-362
Keywords extraction system (effect of); statistical method; Virgin olive oil;
Abstract The extraction methods of virgin olive oil affect the quantification values of some chemical compounds. Statistical tests and procedures have been applied to a set of 142 samples collected from all over Andalusia and characterized by 55 chemical compounds It has been estimated that two aliphatic alcohols one sterol and one fatty acid have the best significance levels identifying the extraction methodology (pressure centrifugation) Stepwise Lineal Discriminant procedure has been used to characterize olive oils by the extraction systems 205 samples from other provinces; varieties or harvests were used to verify these decision equations.
Authors Aparicio López R; Ferreiro L; Leardi R; Forina M
Title Building decision rules by chemometric analysis: application to olive oil
Journal Chemometrics and Intelligent Laboratory Systems, 10, 349-358
Abstract A data set of 97 samples of olive oil characterized by 36 chemical compounds; collected in Jaen (Spain), was used to investigate whether the information obtained by chemometric analysis of all of the variables, considered as a whole, could also be achieved by independent and parallel studies of its subsets. Each one of the subsets introduced independent and uncorrelated information, which can be used to build decision rules which may be implemented in expert systems.
Authors Mariani C; Fedeli E; Grob K; Artho A
Title Indagine sulle variazioni dei componenti minori liberi ed esterificati di oli ottenuti da olive in funzione della maturazione e dello stoccaggio
Journal Rivista Italiana delle Sostanze Grasse, 68, 179-186
Keywords maturazione; olive;
Abstract In the present work variations in the free and esterified minor components occurring during maturation stages and storage of olives are examined. The main variations are to be charged to free triterpenic alcohols: in particular; during maturation it is remarked an increase of 24-methylenecycloarthenol while cycloarthenol and citrostadienol tend to decrease. Esterified triterpenic alcohols present during maturation period the same trends remarked for the free ones, with more evident variations. In stored olives all examined compounds are higher, the higher per cent increase being to the charge of waxy fraction. The authors examine also oils obtained from olives spontaneously fallen from the trees and stored: besides the free acidity increase a general increase of all minor components is remarked, particularly for free stigmasterol and all esterified components. Interesting is the behavior of a-tocopherol, present in all low acidity oils, but not detectable in the ones with a higher content of free fatty acids.
Authors Serani A; Piacenti D
Title Kinetics of Pheophytin-A Photodecomposition in Extra Virgin Olive Oil
Journal Journal of the American Oil Chemists Society, 69, 469-470
Keywords Activation energy; chlorophyllian pigments; extra virgin olive oil; first-order reaction; frequency factor; HPLC analysis; kinetic constant; luminous energy; pheophytin-A; photodecomposition;
Abstract The amount of pheophytin-A in extra olive oil was determined by reverse-phase high-performance liquid chromatography (HPLC) with chlorophyll-A as an internal standard. The kinetics of pheophytin_A photodecomposition at 15;40 and 50º C at three different luminous energies were studied. The pheophytin-A photodecomposition process develops according to a first-order reaction. From the Arrhenius' straight lines, it appears that the incident luminous energy does not change the activation energy but increases the reaction frequency factor.
Authors Calapaj R; Chiricosta S; Saija G; Bivona Y
Title Valutazione di risultanze analiche gascromatografiche e spettrofotometriche nell'accertamento della presenza di oli di semi in campioni di olio di oliva
Journal Rivista Italiana delle Sostanze Grasse, 70, 585-594
Keywords gascromografiche; spettrofotometriche;
Abstract 162 vegetable oil samples declared olive oils have been subjected to gaschromatographic analyses for the determination of the sterols and derivative type spectrophotometric investigations (D''K232; D''K241, D''K247, D''K257, D''K268, D''K279, D''K302, D''K316) to ascertain the presence of seed oils. In the 86.42% of the cases it is noticed an excellent agreement between the derivative spectrophotometric values and the content of sterols.
Authors Santinelli F; Damiani P; Christie WW
Title The Triacylglycerol Structure of Olive Oil Determined by Silver Ion High-Performance Liquid Chromatography in Combination with Steriospecific Analysis
Journal Journal of the American Oil Chemists Society, 69, 552-556
Keywords Chiral chromatography; diacylglycerols; high-performance liquid; olive oil (Olea europaea); silver ion chromatography; stereospecific analysis; triacylglycerol;
Abstract The compositions of positions sn-1;sn-2 and sn-3 of triacylglycerols from 'extra-virgin' olive oil (Olea europaea) were determined. The procedure involved preparation of diacyl-rac-glycerols by partial hydrolysis with ethyl magnesium bromide; 1,3-,1,2- and 2,3-diacyl-sn-glycerols as (S)- (+)-1-(1-naphthyl) ethyl urethanes were isolated by high-performance liquid chromatography (HPLC) on silica, and their fatty acid compositions were determined. The same procedure was also carried out on the five main triacylglycerol fractions of olive oil after separations according to the degree of saturation by HPLC in the silver ion mode. Although stereospecific analysis of the intact triacyl-sn-glycerols indicated that the compositions of positions sn-1 and sn-3 were similar, the analyses of the molecular species demonstrated marked asymmetry. The data indicate that the '1-random, 2-random,3-random' distribution theory is not always applicable to vegetable oils.
Authors Gutiérrez F; Perdiguero S; García JM; Castellano JM
Title Quality of Oils from Olives Stored Under Controlled Atmosphere
Journal Journal of the American Oil Chemists Society, 69, 1215-1218
Keywords cold storage; controlled atmosphere; olives; Olea europaea; olive oil; quality;
Abstract Olive (Olea europaea cv. ' Picual ') fruits were stored under five different storage conditions (ºC/ % CO2/ %O2: ambient; 5:0:21; 5:3:20; 5:3:5; and 5:<1:5) to determine their influence on the chemical and sensorial quality of oil extracted from the olives at the end of the storage period. Results showed that storage of fruits at 5ºC prevented the fast alteration that is produced in oils extracted from fruits stored at ambient temperatures. The use of controlled atmosphere at 5ºC with 3% CO2 and/ or 5% O2 did not present clear advantages on acidity; peroxide value, K270 and K232 coefficients, stability and sensorial quality. Cooling of fruit keeps physical, chemical and sensorial characteristics of oil below maximum established values for the period of time assayed (60 d).
Authors Salivaras E; McCurdy AR
Title Detection of Olive Oil Adulteration with Canola Oil from Triacylglycerol Analysis by Reversed-Phase High-Performance Liquid Chromatography
Journal Journal of the American Oil Chemists Society, 69, 935-938
Keywords 'low-linolenic' canola varieties; Adulterations of olive oil; Canola oil; Composition; fatty acids; GLC; reversed-phase HPL; seed oils; triacylglycerol analysis; Virgin olive oil;
Abstract The objective of this study was to explore the use of reversed-phase high-performance liquid chromatography (RP-HPLC) as a means to detect adulteration of olive oil with less expensive canola oil. Previously this method has been shown to be useful in the detection of some other added seed oils; however; the detection of adulteration with canola oil might be more difficult due similarities in fatty acid composition between canola oil and olive oil. Various mixtures of canola oil with olive oils were prepared, and RP-HPLC profiles were obtained. Adulteration of olive oil samples with less than7.5% (w/w) canola oil could be detected.
Authors Mínguez-Mosquera MI; Gandul Rojas B; Gallardo-Guerrero ML
Title Rapid Method of Quantification of Chlorophylls and Carotenoids in Virgin Olive Oil by High-Performance Liquid Chromatography
Journal Journal of Agricultural and Food Chemistry, 40, 60-63
Keywords carotenoids; chlorophyll; high-performance liquid chromatography; Quantification; Virgin olive oil;
Abstract The fatty material of olive oil was separated; yielding a fat-free concentrate of pigments, by solid-phase extraction on octadeclyl (C18) columns. The study of recovery carried out with lutein and pheophytin a gave an excess error lower than 4%. A total of pigments was separated from this extract and quantitified by HPLC using a reversed-phase C18 column. The method consisted of an elution gradient of 2 mL/min of water-ionic reagent-methanol (1:1:8) and methanol-acetone (1:1). Detection was performed by absorption at 410 and 430 nm and quantification from the straight lines of calibration of each analytically pure standard. The application of this technique to five monovariety virgin olive oils showed that pigment content among them is very different, depending on the variety of olive.
Authors Montedoro GF; Servili M
Title Il parametri di qualitá dell'olio di oliva ed i fattori agronomici e tecnologici che li condicionano
Journal Rivista Italiana delle Sostanze Grasse, 69, 563-573
Keywords olive oil quality;
Abstract Virgin olive-oil quality is linked to marketable, nutritional and organoleptic parameters. These parameters are in relationship to agronomic and technological aspects. Among the agronomic factors, fruit ripening, cultivar and agroclimatic conditions were examined to evaluate their effects on some minor compounds of oil.
Regarding the technological aspects, fruit storage, malaxation, and extraction technology were evalued in relation to some compounds responsible for organoleptic oil quality. From the data collected, it can be concluded that, the phenol compounds have an important role in the virgin olive-oil quality.
Authors Morales MT; Aparicio López R; Gutiérrez F
Title Técnicas de aislamiento y concentración de volátiles de aceites vegetales
Journal Grasas y Aceites, 43, 164-173
Abstract Uno de los métodos de evaluación del flavor de los alimentos consiste en la determinación de sus componentes volátiles. La primera etapa necesaria para la realización de este tipo de análisis es el aislamiento y concentración de los mismos. Se ha realizado una versión bibliográfica sobre las diferentes técnicas utilizadas para este fin en diferentes alimentos y especialmente en aceites vegetales. Los métodos utilizados son muy diversos; se ofrece una explicación de cada uno de ellos considerando las diferentes variantes existentes. Asimismo se detallan las aplicaciones realizadas en aceites vegetales durante los últimos años.
Authors García Pulido J; Aparicio López R
Title Estimating triacylglycerols from fatty acids by chemometrics. An application in Spanish virgin olive
Journal Grasas y Aceites, 43, 193-197
Keywords chemometrics study; fatty acid; triglycerides(composition); Virgin olive oil;
Abstract The level of acceptation of ' 1; 3-random 2-random ' pattern of acyl groups distribution in virgin olive oil glycerides has been analyzed in 36 samples, by comparing the values of triacylglycerols obtained by HPLC with those reported by the cited theory. Hotelling's T2,Principal Components and Canonical Correlation Analysis have been used to study both data sets. The normality of the data distributions, the intra- and intergroup correlations of the triacylglycerols were studied before these multivariate statistical algorithms were applied. An alternative way of estimating triacylglycerols from only total fatty acids has also been studied. A Stepwise Multiple Regression procedure has been employed, and Multiple R coefficients fluctuate between 0,75 and 0,94 except for the variable SOS.
Authors Sacchi R; Addeo F; Giudicianni I; Paolillo L
Title Analysis of the Positional Distribution of Fatty Acids in Olive Oil Triacylglycerols by High Resolution 13C-NMR of the Carbonyl Region
Journal Italian Journal of Food Science, 4, 117-123
Keywords high resolution carbon-13 NMR; carbonyls; positional distribution; fatty acids; triacylglycerols; olive oils; esterified oils;
Abstract The determination of the content of saturated fatty acids in positions 1.3-and 2- of triacylglycerols of olive oil was carried out using high resolution carbon-13NMR spectroscopy. The method described here relies on the difference in chemical shift observed experimentally for the carbonyl resonances of different fatty acids esterified both in glycerol positions 1;3- and 2-. This work outlines an analytical method to detect synthetic esterified oils in mixtures with virgin olive oils. The advantage of 13C-NMR is that the oil sample can be directly analyzed, thus avoiding chemical procedures.
Authors Pérez Camino MC; García JM; Castellano JM
Title Polar Compound Concentrations in Virgin Oils from Stored Cultivar Picual Olive Fruits
Journal Journal of Agricultural and Food Chemistry, 40, 2260-2262
Keywords concentration; fruits; Picual; polar; virgin olive oil;
Abstract Olive fruits (Olea europea cv. Picual) were stored for up to 60 days under five different storage conditions: three in controlled atmosphere at 5ºC (air +3%CO2; 5% O2 + 3% CO2; 5% O2 +<1% CO2) and two in air (one at environmental temperature (between 6 and 17º C) and the other in cold room at 5ºC). After conservation; The oils were extracted from the fruits and non polar compounds (mainly non altered triglycerides) and polar compounds (triglyceride polymers, oxided triglyceride monomers, diglycerides, monoglycerides, and fatty acids) were determined. Polar compounds were determined by high-performance size exclusion chromatography after non altered compounds were discarded by column chromatography. The results demonstrated that storage of olive fruits at 5ºC produced a lesser amount of polar compounds in the oils extracted from them, compared to classical conservation (environmental temperature). At 5ºC neither increasing CO2 to 3% nor decreasing 02 to3% nor decreasing 02 to 5% affords additional advantages as compared to storage in air.
Authors Sánchez J; Del Cultivo MT; Harwood L
Title Glycerolipid Biosynthesis by Micromomal fractions from Olive Fruits
Journal Phytochemistry, 31, 129-134
Keywords biosynthesis; glycerolipids; Olea europaea; Oleacea; olive fruits; triacylglycerols;
Abstract Microsomal fractions prepared from maturing olive (Olea europea cv Picual) fruits incorporated label from oth [14C]palmitoyl-CoA and [14C]oleoyl-CoA into several glycerolipids, including triacylglycerols. The preparations contained high acyl-CoA thioesterase activity which was inhibited by Mg2+ and bovine serum albumin. Incorporation into glycerolipids was strongly stimulated by Mg2+, whereas addition of ATP was inhibitory; a low stimulation by glycerol-3-phosphate was observed. Under all conditions used oleoyl-CoA was a better substrate for glycerolipid synthesis than palmitoyl-CoA, whereas the latter seemed to be a better substrate for the acyl-CoA thioesterase.
Authors García-Mesa J. A.; Luque de Castro M. D.; Valcárcel M.
Title Direct automatic determination of bitterness in virgin olive oil by use a flow-injection-sorbent extraction system
Journal Analytica Chimica Acta, 261, 367-374
Keywords flow system; spectrophotometry; bitterness; extraction; olive oil;
Abstract An automated version of an existing bath method for the determination of bitterness in virgin olive oil was developed. The automatic method is based on flow-injection analysis (FIA) principles and is implemented by coupling an FIA manifold to a solid - liquid retention unit in which the sample matrix is retained on a C18- bonded silica- packed minicolumn; the analytes being monitored by UV spectrophotometry and the retained matrix being eluted in the opposite direction to detection, so it never reaches the detector. The automatic method clearly surpasses its manual counterpart in terms of solvent savings, analysis time (5 vs. 50 min) and labour requirements (none of the tedious preliminary steps of the manual method need be implemented).
Authors Montedoro GF
Title I fattori tecnologici responsabili della qualitá degli oli vergini di oliva
Journal Oliveto, 5, 6-11
Keywords Virgin olive oil;
Authors Tsimidou M; Papadopoulos G; Boskou D
Title Determination of phenolic compounds in virgin olive oil by reversed-phase HPLC with emphasis on UV detection
Journal Food Chemistry, 44, 53-60
Keywords olive oil; Phenolic compounds; polyphenols; RP-HPLC;
Abstract A method is described for the chromatographic separation and quantitative determination of phenolic compounds in virgin olive by high-performance liquid chromatography (HPLC) using gradient elution. For the determination of individual compounds molar absorptivities at 280nm are calculated. A technique based on the use of four external standards (tyrosol; vanillic acid, syringic acid, o-coumaric acid) is applied in order to minimize errors due to different lmax and e280. The method was applied successfully to olive oil samples.
Authors Grob K; Artho A; Mariani C
Title Determination of Raffination of Edible Oils and Fats by Olefinic Degradation Products of Sterols and Squalene, Using Coupled LC-GC
Journal Fatty Science Technology, 94, 394-400
Keywords Coupled LC-GC; edible oils; sterols;
Abstract Raffination of edible oils and fats; i.e. bleaching with earth or charcoal as well as deodoration, can be determined by the analysis of dehydroxylation products of sterols and isomerization products of squalene. These olefinic degradation products are isolated from the rest of the oil by LC on silica gel and on -line transfer to GC. Sample preparation consists of preparing a 20% solution of the oil. Nearly half of the ' extra virgin' olive oils analyzed contained such products, but concentrations were too low for assuming admixture of regularly refined oils. However, many other oils advertized as non-refined turned out to have been treated beyond declaration.
Authors Chryssafidis D; Maggos P; Kiosseoglou V; Boskou D
Title Composition of Total and Esterified 4a-Monomethylsterols and Triterpene Alcohols in Virgin Olive
Journal Journal of the Science of Food and Agriculture, 58, 581-583
Keywords Capillary column gas chromatography; column-thin layer chromatography; esterified monomethylsterols and triterpene alcohols; olive oil;
Abstract Esterified 4a-monomethylsterols and triterpene alcohols were isolated from virgin olive oil by combined column chromatography-thin layer cromatography and their composition was assessed gas chromatographically using both packed and capillary columns. The composition of the esterified 4a-mono-methylsterol and triterpene alcohol fractions were compared with those of the total fractions which were isolated after saponification. Significant differences were observed between the distribution patterns of the total and esterified triterpene alcohol fractions; especially in the percentages of 24-methylenecyclo-artanol, butyrospermol and cycloarthenol.
Authors Aparicio López R; Gutiérrez F; Rodríguez-Morales J
Title Relationship between Flavour Descriptors and Overall Grading of Analytical Panels for Virgin
Journal Journal of the Science of Food and Agriculture, 58, 555-562
Keywords analytical panel; chemometrics; olive oil; sensory analysis;
Abstract An analytical panel is used to evaluate the quality of virgin olive oil. Two regression procedures- step-wise multiple regression and regression on principal components -have been used to construct equations that relate profile to overall grading of 57 samples of virgin olive oil collected from all over Spain. Every equation has an adjusted R2>0;94. Forty new samples evaluated by another panel were used to verify the models. Regression on the principal components correctly classified 87,5% of samples, against 95% classified by step-wise multiple regression. Kurtosis, outliers, multicollinearity and singularity were also studied before building the regression models.
Authors Montedoro GF; Servili M; Baldioli M; Miniati E
Title Simple and Hydrolysable Phenolic Compounds in Virgin Olive Oil. 2. Initial Characterization of the Hydrolysable Fraction
Journal Journal of Agricultural and Food Chemistry, 40, 1577-1580
Keywords olive oil; Characterization;
Abstract This paper reports the preliminary characterization of unknown phenolic compounds in virgin oliveoil, separated by HPLC using hydrolytic, chromatographic, and spectrophotometric techniques. It waspossible to characterize oleuropeine aglycon and three hydrolyzable phenols containing (3,4-dihydroxyphenyl)ethanol or p-hydroxyphenyl)ethanol.
Authors Angerosa, F.; Di Giacinto, L.; Solinas, M,;
Title Influence of Dacus Oleae infestation on flavor of oils, extracted from attacked olive fruits, by HPLC and HRGC analyses of volatile compounds
Journal Grasas y Aceites, 43, 134-142
Keywords Dacus Oleae; Flavor; Infestation (influence of); Oil; Volatile components;
Abstract The authors have examined the influence of the Dacus Oleae infestation on the aroma of the oils obtained from olives Coratina and Nebbio varieties at different levels of attack. The results obtained indicated a worsening of the qualitative level of the obtained from increasing percentages of infested olives; these were found to have a great decrease of phenolic substances and higher contents of both volatile alcohols and aldehydes with an7unpleasant sensation. Of particular interest hexanal/total volatile alcohols ratio; in which having been well correlated with the extent of infestation, would permit one to establish in an objective manner, if and how much the olives from which an oil has been extracted have suffered a Dacus attack.
Authors Mariani C; Venturini S; Bondioli P; Fedeli E; Grob K
Title Valutazione delle variazioni indotte dalla decolorazione sui principali componenti minori liberi ed esterificati dell'olio di oliva
Journal Rivista Italiana delle Sostanze Grasse, 69, 393-399
Keywords decolorazione; esterification; variazioni;
Abstract The Authors evaluate the quali- and quantitative variations occurring on principal minor components free and esterified during bleaching with activated earths. during this process the minor free components are subjected to remarkable reduction that sometimes bring to their complete loss with a great alteration of the analytical configuration. As regards to the esterified minor components (waxes; sterol esters and triterpenic alcohols) they are subjected to more limited reductions, showing a higher resistance to bleaching hearth action. Remarkably interesting is the isomerization occurring in squalene during bleaching; these isomers, as already pointed out, testify a bleaching operation and their characterization can represent a useful mean to detect the addition of bleached oils in virgin ones.
Authors Aparicio López R; Graciani E; Ferreiro L
Title Chemometric study of the Hilditch theory applied to virgin olive oil
Journal Analytica Chimica Acta, 259, 115-122
Keywords liquid chromatography; canonical correlation; Hilditch's theory; olive oils; principal component analysis; triacylglycerols;
Abstract Thirty-six samples of virgin olive oil; characterized by ten triacylglycerols and their total and b-position fatty acids, were analyzed in order to establish the level of acceptation of Hilditch's theory for this fat. Hotelling's T2 and canonical correlation and principal components algorithms were used to study both sets of data. The algorithms relating to sample distribution, explained variance and redundancy index, among others, were computed as a method of establishing whether the computed canonical correlation (0,95) is based on a robust statistical background.
Authors Capasso R; Cristinzio G; Evidente A; Scognamiglio F
Title Isolation Spectroscopy and selective phytotoxic effects of polyphenols from vegetable waste waters
Journal Phytochemistry, 31, 4125-4128
Keywords acetates; chromatographic isolation; Olea europea; Oleaceae; olive oil waste wasters; polyphenols; phytotoxicity;
Abstract Catechol; 4-methylcatechol, tyrosol and hidroxytyrosol were isolated and characterized as the main polyphenols from olive oil mill waste waters. In addition the corresponding acetates were prepared. In phytotoxicity assays carried out on tomato (Lycopersicon esculentum) and vegetable marrow (Cucurbita pepo) plants, the compounds were selectively toxic, except for 4-methylcatechol and its acetate. The vegetation waters remained phytotoxic even after total extraction of the polyphenols, suggesting that other chemical products contribute to the overall phytotoxicity.
Authors Montedoro GF; Servili M; Baldioli M; Miniati E
Title Simplex and Hydrolysable Phenolic Compounds in Virgin Olive Oil. 1. Their Extraction, Separation, and Quantitative and Semiquantitative. Evaluation by HPLC
Journal Journal of Agricultural and Food Chemistry, 40, 1571-1576
Keywords extraction; HPLC; Simplex; Virgin olive oil;
Abstract This papers reports the preliminary characterizations of unknown phenolic compounds in virgin olive oil; separated by HPLC using hydrolytic, chromatographic, and spectrophotometric techniques. It was possible to characterize oleuropeine aglycon and three hydrolysable phenols containing (3,4-dihydroxyphny) ethanol or (p-hydroxyphenyl) ethanol.
Authors Solinas M
Title Principios de la extracción del aceite de las aceitunas
Journal Olivæ, 42, 31-35
Keywords extraction olive oil;
Authors Ferreiro L; Aparicio López R
Title Influencia de la Altitud en la Composición Química de los Aceites de Oliva Vírgenes de Andalucía. Ecuaciones matemáticas de clasificación
Journal Grasas y Aceites, 43, 149-156
Keywords Aceite de oliva virgen; Altitud (influencia de); Análisis multivariante; Andalucía; Composición
Abstract La influencia del clima en la composición química del aceite de oliva virgen es un campo de investigación que ha sido escasamente estudiado. En el presente trabajo se expone el estudio de esta relación; realizado para Andalucía a través de un parámetro indirecto como es la altitud de las zonas de cultivo. Se ha encontrado que parámetros como los esteroles, y algunos alcoholes e hidrocarburos triterpénicos presentan variaciones sensibles en función de la altitud. Estas variaciones han servido para diferenciar los aceites procedentes de olivares de valle de los procedentes de montaña, utilizando técnicas de análisis discriminantes y de regresión. Las ecuaciones obtenidas se han verificado con aceites de las cosechas de 1988 y 1989, encontrándose una significativa capacidad predictiva (más del 90%) cuando la variedad del olivar es una constante.
Authors Proto M
Title Indagine sui contenuti di acido linoleico e trilinoleina in alcuni oli di semi e di oliva
Journal Industrie Alimentari, 31, 36-39
Keywords seed; linoleic acid; LLL;
Authors McGill AS; Moffat CF; Mackie PR; Cruickshank P
Title The Composition and Concentration of n-Alkanes in Retail Samples of Edible Oils.
Journal Journal of the Science of Food and Agriculture, 61, 357-362
Keywords edible oils; hydrocarbons; n-alkane; vegetable oils;
Abstract A range of edible oils were purchased from a variety of retail outlets and analyzed for their n-alkane (S3315) content. The concentrations ranged from 7 to 166 mg kg-1; the lowest being walnut oil and the highest sunflower oil, n-alkanes with chain lengths of C27, C29 and C31 predominated in all of the plant oils except olive oil were C23, C25 and C27 were the most significant. The results of this pilot survey suggest that the n-alkanes are indigenous and that their composition may be useful in characterizing a specific plant seed oil. Two of the 42 samples analyzed showed markedly different alkane patterns in which profiles similar to petroleum based sources dominated the contribution from odd carbon n-alkanes typical of seed oils.
Authors Carelli AA; Cert Ventulá A
Title Comparative study of the determination of triacylglycerol in vegetable oils using chromatographic techniques
Journal Journal of Chromatography, 630, 213-222
Keywords vegetable oils; triacylglycerol; chromatographic techniques; HPLC; HPLC-RI;
Abstract The triacylglycerols of some vegetable oil samples were determined using isocratic HPLC with refractive index (RI) detection; gradient solvent HPLC with evaporative light scattering detection (ELSD), capillary GC and theoretical calculations from FAME analysis in order to establish the suitability of these techniques. The response factors and the repeatability were investigated. Generally, the HPLC-RI detection technique can be used without application of response factors. HPLC-ELSD yields inaccurate results for low concentrations. Calculations assuming a 1.3- random 2-random distribution of fatty acids gave good results for olive oil and acceptable results for sunflower oil. The GC analysis requires the use of response factors.
Authors Alessandri S
Title Modelos de clasificación aplicados a los análisis químicos para el estudio del origen y de las características de los aceites de oliva
Journal Olivæ, 47, 52-59
Keywords Characterization; classification; authenticity;
Authors García-Mesa JA; Luque de Castro MD; Valcárcel M
Title Couple Robot--Flow Injection Analysis System for Fully Automated Determination of Total Polyphenols in Olive Oil.
Journal Analytical Chemistry, 65, 3540-3542
Authors Tsimidou M; Karakostas KX
Title Geographical Classification of Greek Virgin Olive Oil by Non-parametric Multivariate Evaluation of Fatty Acid Composition
Journal Journal of the Science of Food and Agriculture, 62, 53-257
Keywords fatty acids; geographical classification; Greek olive oil; non-parametric discriminant analysis; principal component analysis;
Abstract Fatty acid compositional data for Greek virgin olive oils from 24 years of harvest and various regions and cultivar were evaluated using chemometric methods. Non-parametric discriminant analysis after proper transformation of the data seems to be a suitable approach to characterize the oils according to the geographical origin and may produce a scientific basis for the assignment of an 'appellation d' origine' trade mark.
Authors Olías JM; Pérez AG; Rios JJ; Sánz LC
Title Aroma of Virgin Olive Oil: Biogenesis of the 'Green' Odor Notes
Journal Journal of Agricultural and Food Chemistry, 41, 2368-2373
Keywords Virgin olive oil; green odor notes; biogenesis;
Abstract The enzymes acylhidrolase; lipoxigenase, and fatty acid hydroperoxide lyase were found in cell-free extract of olive fruit. Triaglicerols and phospholipids are hydrolyzed to free fatty acid, mainly polyunsaturated, by acylhidrolase. From linoleic and linoleic acids 9-and 13-hydroperoxides were formed by lipoxigenase. The lyase cleaves the 13-hydroperoxides of linoleic and linolenic acids to form the volatiles aldehydes hexanal and cis-3-hexanal, respectively; the enzyme does not act on 9-hydroperoxides of these acids. Incubation of ripe olive fruit tissue disk resulted in biological conversion of hexanal and trans-2-hexanal to corresponding alcohols. Hexyl alcohols were converted to their acetate esters during the incubation with olive fruit tissue. A sequential enzymatic pathway for the formation of green odor compounds in virgin olive proposed.
Authors Morales MT; Aparicio López R
Title Optimization by mathematical procedures of two dynamic headspace techniques for quantifying virgin olive oil volatiles
Journal Analytica Chimica Acta, 282, 423-431
Keywords Chromatography; headspace techniques; virgin olive oil volatiles; olive oil;
Abstract Two dynamic headspace techniques; using activated charcoal with on-column injection and Tenax TA with thermal desorption and cold trap injection, were studied and applied to Spanish virgin olive oil samples. Optimum responses taking into account an overall desirability function were detected by Simplex method and response surfaces were built. Isobutyl acetate, among three considered, was the best standard for both techniques. Finally, the of trials and injections (testing schemes) for both techniques were studied considering the variance and laboratory expenses and time as factors to decide the optimum.
Authors Montedoro GF; Servili M; Baldioli M; Selvaggini R; Maniati E; Macchioni A
Title Simple and Hydrolysable Compounds in Virgin Olive Oil. 3. Spectroscopic Characterizations of the Secoiridoid Derivatives
Journal Journal of Agricultural and Food Chemistry, 41, 2228-2234
Keywords Characterization; Virgin olive oil; derivatives;
Abstract Phenolic compounds are important in relation to nutritional and sensory characteristics and the shelflife of virgin olive oil. Four new phenolic compounds have been separated by HPLC. The compounds are two (3,4-dihydroxyphenyl)ethanol derivatives and two @-hydroxypheny1)ethanol derivatives. This paper reports the NMR, IR, and UV characterization of three of these phenolic compounds. The compounds identified are an isomer of oleuropeine aglycon, the dialdehydic form of elenolic acid linked to (3,4-dihydroxyphenyl)ethanola,n d the dialdehydic form of elenolic acid linked to @-hydroxyphenyl)-ethanol.
Title El mercado internacional del aceite de oliva
Journal Olivæ, 15-17
Keywords Aceite de oliva; mercado internacional;
Authors Kaya A; Tekin AR; Oner MD
Title Oxidative Stability of Sunflower and Olive Oils: Comparison between a Modified Active Oxygen Method and Long Term Storage
Journal Lebensmittel-Wissenschaft und-Technologic, 26, 464-465
Keywords stability; sunflower; olive; storage;
Abstract Shelf-lives of sunflower oil and olive oil were estimated using an Accelerated Shelf-life Testing (ASLT) method and these were compared with the values in long term storage. In addition; the effect of type, oxygen permeability, and transparency of the packages on the shelf-lives of oils were investigated. The determinations were based on the oxidative stability of oils by measuring their peroxide values. The limiting peroxide value corresponding to the end of shelf-life was obtained from the FAO/WHO standards. The shelf-lives of sunflower and olive oil samples in retail store conditions were estimated at 10.6 and 20.8 mo, respectively. storage lives of sunflower oil in polyethylene tere-phthalate (PET), clear gas and color glass bottles under a 10 W fluorescence lamp were 10.4, 11.1 and 11.8 mo at 10ºC, and 4.8, 5.1 and 6.5 mo at 20ºC, respectively. Long term storage lives of olive oil in PET, clear and colored glass were 17.5, 17.8 and 18.3 mo at 10ºC, and 8.0, 8.4 and 8.7 mo at 20ºC, respectively. These long term storage lives were them compared with the ASLT results obtained from the modified active oxygen method using a simple shelf-life plot approach.
Authors Kiritsakis AK
Title Química del aroma del aceite de oliva
Journal Olivæ, 45, 28-33
Keywords Aroma; olive oil; aroma chemistry;
Authors Hidalgo Casado F; Navas Fernández MA; Guinda Garín A; Ruiz Gómez MA; León Camacho M; Lanzón A; Maestro Durán R; Janer del Valle ML; Pérez Camino MC; Cert Ventulá A; Alba Mendoza J; Guitiérrez Rosales F; Dobarganes García MC; Graciani Constante E
Title La calidad del aceite de oliva: Posibles nuevos criterios para su evaluación
Journal Grasas y Aceites, 44, 10-16
Keywords extraction system (effect of); Quality (criterion); Virgin olive oil;
Abstract The present study consists in the evaluation of twenty five parameters for determining the influence of continuous system of pastes centrifugation; discontinuous press system and partial extraction system on obtention of virgin olive oil, and their possible utilization as new quality parameters. Also, those indexes more related to quality than to spoilt degree (acid value, peroxide value and K270) were determined. The tested oils have been obtained in three oil-mills, from three different olive varieties, in two ripening states.
Authors Mariani C; Gasparoli A; Venturini S; Fedeli E
Title Strutto vergine e strutto raffinato: loro differenziazione analitica
Journal Rivista Italiana delle Sostanze Grasse, 70, 275-278
Keywords Virgin and Refined Lard;
Abstract The distinction between virgin and refined lard is carried out usually by UV spectrophotometry at 268 nm that measures the trienic conjugation fundamentally induced by the bleaching process. The UV determination nevertheless is especially in presence of oxidized products with an absorbance between 225 and 325 nm. During the refining process; and above all during the bleaching stage with activated earths, a dehydroxylation of free sterols takes place with the production of steroidic hydrocarbons characterized by a double bond conjugated in 3 and 5. The production of these hydrocarbons is independent from the oxidation degree of fatty materials but is a function of the decoloration process with activated earths and, in a lower measure, of the deodorization especially carried out over 230ºC. Consequently the determination of steroidic hydrocarbons represents a method for the evaluation of the products submitted to decoloration or deodorization process (>230ºC).In this work a method is presented for the determination of 3,5-cholestadiene coming from cholesterol dehydroxylation, that allows to evaluate lards bleached by activated earths (or deodorized over a temperature of 230ºC), also in presence of oxidation products that could interfere on UV absorbances.
Authors Fedeli E
Title La valutazione organolettica degli oli vergini di oliva
Journal Rivista Italiana delle Sostanze Grasse, 70, 81-85
Keywords Virgin olive oil;
Abstract On the methodology ' Panel test ' we dispose at present of sufficient data to allow a statistical elaboration directed to consider repeatability; reproducibility and the parameters affecting them. Moreover, the regression analysis allows observations of remarkable interest on statistical data determining the final score.
Authors Guth H; Grosch W
Title Quantitation of Potent Odorants of Virgin Olive Oil by Stable-Isotope Dilution Assays
Journal Journal of the American Oil Chemists Society, 70, 513-518
Keywords Capillary gas chromatography; isotope dilution assay; mass spectrometry; odor activity value; odor evaluation; odorant; quantitation;
Abstract The potent odorants of four olive oil samples differing in flavor were quantitated; and their odor activity values (OAVs) were calculated by dividing the concentrations of the odorants in the oil samples by the flavor threshold values in the oil. The odorants with higher OAVs were contrasted with the different notes of the flavor profiles of the olive oils. It was concluded that the following compounds contributed mainly to the flavor notes given in parentheses: (Z) -3-hexenal (green), ethyl 2-methylbutyrate, ethyl isobutyrate, ethyl cyclohexanoate (fruity), (Z)- 2-nonenal (fatty) and 4- methoxy-2-methyl-2-butanethiol (black-currant-like). The results showed that the calculation of OAVs is an approach to objectify the flavor differences of olive oil samples.
Authors Gigliotti C; Daghetta A; Sidoli A
Title Indagine conoscitiva sul contenuto trigliceridico di oli extra vergini di oliva di varia provenienza
Journal Rivista Italiana delle Sostanze Grasse, 70, 483-489
Keywords Triglycerides in olive oils extra virgin;
Abstract Fatty acid and triglyceride compositions of 123 extra virgin olive oil samples; from the mediterranean basin, were determined. The attribution of the main peaks to the respective triglycerides was achieved by the use of pure standard solutions and the development of mathematical models. The comparative evaluation of the results showed for some triglycerides the presence of quantitative intervals which can be to correlated with the geographic origin of the samples.
Authors Capella P
Title Análisis del Aceite de Oliva
Journal Olivæ, 45, 24-27
Authors Amr S; Abu-Al-Rub AI
Title Evaluation of the Bellier Test in the Detection of Olive Oil Adulteration with Vegetable Oils
Journal Journal of the Science of Food and Agriculture, 61, 435-437
Keywords olive oil; Bellier test; Adulteration; vegetable oils; seed oils;
Abstract Virgin olive oil was mixed with eight vegetable oils (sunflower; soya bean, palm, linseed, cottonseed, corn,sesame and olive residue) at various levels. The Bellier test was applied to find the minimum detectable adulteration level and the 'sensitivity score' for each oil. The test was inapplicable to sunflower and linseed oils regardless of the level in olive oil. It was successful in detecting olive residue, soya bean, palm, cottonseed, corn and sesame oils at minimal levels of 730, 150, 130, 90, 60, and 10 g kg-1, respectively. The rancidity level of the adulterant oils did not affect the performance of the test in the case of sunflower, linseed and sesame oils. The sensitivity of the test decreased considerably with increasing peroxide value of the adulterant oil: soya bean, palm, cottonseed, corn, and olive residue. However, the change in sensitivity level commenced at so high a peroxide value that it has no significance for practical purposes; at such levels of peroxidation the adulterated olive would be unmarketable and rejected by inspectors due to its poor sensory quality.
Authors Castellano JM; García JM; Morilla A; Perdiguero S; Gutiérrez F
Title Quality of Picual Olive Fruits Stored under controlled Atmospheres
Journal Journal of Agricultural and Food Chemistry, 41, 537-539
Keywords picual olive fruits;
Abstract Olive (Olea europaea cv. Picual) fruits were stored under different conditions of controlled atmosphere (CA) and temperature. Decay incidence for olives kept at ambient temperatures (6-17ºC; 65-70% relative humidity) reached nearly 100% after 15-30 days; with a rapid decrease in all of the quality indexes assayed. The severe loss of water, because of the low relative humidity, caused shriveling. Storage in air at 5ºC gave the lowest incidence of physiological disorders and decay. Storage at 5ºC and 3% CO2 + 5% O2 for up to 30 days delayed ripening as indicated by retention of green color and flesh firmness. However, this storage system for longer than 30 days resulted in higher incidence of chilling injury and rot.
Authors García Pulido J; Aparicio López R
Title Triacylglycerol determination based on fatty acid composition using chemometrics
Journal Analytica Chimica Acta, 271, 293-298
Keywords fatty acids; gas chromatography; multivariate calibration; olive oil; triacylglycerols;
Abstract Multivariate statistics were applied to analyze the relationships between fatty acids and triacylglycerols in virgin olive oil. The chemical significance of factors obtained by applying principal components analysis to both sets of variables was established; and this method is proposed as a useful tool for obtaining information about the biosynthetic route of fatty acids and is regulation. Finally, because both sets of data present the same latent structure, multiple regression analysis is proposed for determining the triacylglycerol composition of an oil according to its fatty acid composition.
Authors Mariani C; Venturini S; Fedeli E
Title Valutazione di idrocarburi di neoformazione e componenti minori liberi ed esterificati nelle varie classi di oli di oliva
Journal Rivista Italiana delle Sostanze Grasse, 70, 321-327
Keywords esterification; Evaluation of Neo-formation Hydrocarbons;
Abstract In the last years analytical methods for the genuineness determination of olive oils considerably increased. If this increasing produced some advantages for the chemical composition knowledge; on the other hand produced a remarkable increase of economical charge for the analytical laboratories. A reduction or at least a rationalization of the analytical tests are more and more wanted by the utilizers. In the present work an analytical method is proposed that, through one clean-up only enables the determination of steroidic neo-formation hydrocarbons, squalene isomers, tocopherols, squalene, free aliphatic alcohols, free sterols, free triterpenic alcohols, waxes, sterol and triterpenic alcohols esters.
Authors Akasbi M; Shoeman DW; Saari Csallany A
Title High-Performance Liquid Chromatography of Selected Phenolic Compounds in Olive Oils
Journal Journal of the American Oil Chemists Society, 70, 367-370
Keywords caffeic acid; electrochemical detection; HPLC; homovanillic acid; hydroxytyrosol; olive oil; p-hydroxyphenylacetic acid; tyrosol;
Abstract A reverse-phase high-performance liquid chromatographic technique with isocratic elution has been developed to separate and quantitate the major phenolic compounds of the hydroalcoholic extracts of olive oils. Hydroxytyrosol; tyrosol, caffeic acid, p-hydroxyphenylacetic acid and homovanillic acid were analyzed on a mBonapak C18 column with an acetonitrile/water/acetic acid(20:)0:0.18,vol/vol/vol) mixture as a mobile phase. Electrochemical detection provided selectivity as well as sensitivity. The method was applied to the analysis of the most important phenolic compounds in olive oils.
Authors Bondioli P; Mariani C; Armando L; Fedeli E; Muller A
Title Squalene recovery from olive oil deodorizer distillates
Journal Journal of the American Oil Chemists Society, 70, 763-766
Keywords acid; By-product; carbon dioxide; concentration; counter current column; Determination; esters; fatty acid; fractionation; Free fatty acid; liquid-liquid extraction; olive oil; process; Relationship; squalene; super
Abstract Olive oil deodorization distillate contains squalene in a concentration range of 10 to 30 wt%. A process for its recovery by supercritical carbon dioxide extraction is described. The process consists mainly of converting the free fatty acids and the methyl and ethyl esters normally occurring in this by-product into their corresponding triglycerides. The latter are then extracted with supercritical carbon dioxide to provide a highly enriched squalene fraction. The process has been carried out on a pilot-plant scale with a column operating in the countercurrent mode. The relationship between the experimental conditions and squalene purity and yield has been studied. Analytical methods were used for the determination of squalene and other components in the fractions. By use of this process; squalene can be recovered in high purity and yields of about 90%.
Authors Antoniosi Filho NR; Carrilho E; Lanças FM
Title Fast Quantitative Analysis of Soybean Oil in Olive Oil by High-Temperature Capillary Gas Chromatography
Journal Journal of the American Oil Chemists Society, 70, 1051-1053
Keywords Adulteration; Capillary gas chromatography; HRGC; HT-CGC; olive oil; soybean oil; triglycerides;
Abstract Analysis of glycerides has always been of great interest; especially to the food industry. Several methods have been developed, and attempts to improve analytical conditions are prevalent. Among these methods, high-temperature capillary gas chromatography has received particular consideration because it rapidly provides a glyceride profile. In this paper, we discuss a method to identify and quantitate mixtures of olive and soybean oils with the intention of verifying the latter as an adulterant of olive oils. The contamination of olive oil with soybean oil was detected by the presence of the triglyceride trilinolein, which does not exist in pure olive oil, although it is abundant in soybean oil. A calibration curve was constructed with several levels of contamination, and the lowest amount of detectable soybean oil was determined to be 4%.
Authors Mariani C; Fedeli E
Title La cromatografía de gases en el análisis de aceite de oliva
Journal Olivæ, 45, 34-39
Keywords Aceite de oliva; Ácidos grasos Trans; Chromatography;
Authors Di Giovacchino L
Title L'impiego dei preparati enzimatici nella estrazione dell'olio dalle olive con i sistemi continui di centrifugazione.Nota I:risultati di esperienze pluriennali
Journal Rivista Italiana delle Sostanze Grasse, 70, 279-287
Abstract The first news of the use in Italy of enzymes in olives working go back to the 1960's.However; only in the 1970's tests were made in laboratories and in industrial plants using enzymes to help extract olive oil with pressure, centrifugation and percolation systems. Reported results have shown that the use of enzymes determines, under certain conditions, a significant increase in the quantity of the oil extracted with the pressure system, if the olives are not mature, and with combined percolation- centrifugation and percolation- pressure systems. The increase in oil yields is due to the specific effect of enzymes that act upon the cellular structure, helping form larger oil droplets, and upon the oil / water emulsion. Particularly interesting results have been obtained using a new easier to use, liquid enzyme product that has helped reach an increase (4-7%)in oil extraction yields obtained using continuous systems of centrifugation of olive paste. The qualitative characteristics of the oil obtained from olive paste treated with enzymes, have resulted to be unchanged or improved in particular as far as phenolic content and stability to oxidation are concerned.
Authors Maestro Durán R.; Borja Padilla R
Title Actividad antioxidante de esteroles y ácidos orgánicos naturales
Journal Grasas y Aceites, 44, 208-212
Keywords antioxidant activity; information (paper); organic acid; sterol;
Abstract Siguiendo el estudio de tos antioxidantes naturales, se incluyen en este trabajo la vitamina C (ácido ascórbico), la vitamina E (tocoferoles y toco-trienoles) y la provitamina A (β-caroteno. luteína. zeaxantina, isozeaxantina. licopeno, astaxantina y cantaxantina), así como de los derivados de estos compuestos que han sido descritos como antioxidantes, bien sea en pro¬ductos alimentarios o de otros usos, bien en la protección de membranas celulares o subcelulares (in vivo). Se discute su papel como inhibidores de la reacción en cadena de los radicales prooxidantes, por reacción irreversible o por secuestro de estos radicales.
Finalmente, se citan las patentes registradas en los últimos años para estos compuestos, sus derivados y sinergistas.
Authors Maestro Durán R.; Borja Padilla R
Title Actividad antioxidante de las vitaminas C y E y de la provitamina A
Journal Grasas y Aceites, 44, 107-109
Keywords antioxidant; information (paper); provitamin A; vitamin C; vitamin E;
Abstract As a continuation of the study of natural antioxidants; this paper includes vitamin C (ascorbic acid), vitamin E (tocopherols and tocotrienols), and provitamin A (b-carotene, lutein, zeaxanthin, lycopene, astaxanthin) and, as well as those derivatives of these which have been described as antioxidants, either used as food additives or protectants of cell membranes (in vivo). Their role as inhibitors of chain reactions of prooxidant radicals by irreversible reaction or quenching of such radicals is discussed. Finally, patents registered during the last years for these compounds, their derivatives and synergists are cited.
Authors Flor RV; Hecking LT; Martín BD
Title Development of High-Performance Liquid Chromatography Criteria for Determination of Grades of Commercial Olive Oils Part I. The Normal Ranges for the Triacylglycerols.
Journal Journal of the American Oil Chemists Society, 70, 199-203
Keywords Adulteration; HPLC; olive oil; reesterified; refined; refractive index; triacylglycerols;
Abstract Criteria for authentic olive oils were developed from isocratic high-performance liquid chromatography analyses of 99 olive oils from the major Mediterranean producers in the 1983-1986 crop years. Authentic olive oils include extra virgin; virgin and pure or refined oils, but exclude all reesterified and adulterated oils. The extra virgin through pure grades will have a combined area for the LOO (C18:2 C18:1 C18:1), LOP (C18:2 C18:1 C16:0), OOO (C18:1 C18:1 C18:1), POO (C16:0 C18:1 C18:1), POP (C16:0 C18:1 C18:1), and SOO ((C18:0 C18:1 C18:1) peaks between 82.0 and 92.6% of the total area (L, linoleic; O, oleic; P, palmitic; S, stearic).Authentic oils will have ratios of LOO/LOP and OOO/POO that coincide with a line defined by OOO/POO =0.7844 (LOO/LOP)+ 0.0968; correlation coefficient is 0.885. Authentic oils will not have a trilinolein (LLL)peak over 0.5 % in area Neither triolein (OOO) nor any other single peak suffices to characterize an olive oil sample as one of the authentic grades.
Authors Amelio M; Rizzo R; Varazini F
Title Separation of Wax Esters from Olive Oils by High-Performance Liquid Chromatography
Journal Journal of the American Oil Chemists Society, 70, 793-796
Keywords crude pomace oil; detection of adulteration in olive oils; extra virgin olive oil; high-performance liquid chromatography (HPLC); high-resolution gas chromatography (HRCG); liquid chromatography (LC); refined olive oil; separation of wax esters; wax esters;
Abstract To detect adulteration of olive oil with solvent-extracted oils; the determination of the wax ester content has become more important during recent years. Hence, a greater of wax ester analyses need to be performed by quality control laboratories. The most common method in use requires a liquid chromatographic (LC) separation of the less polar fraction, which contains the wax esters, from the glyceride matter on a hand-filled silica gel column. The aim of this project was to verify the possibility of replacing LC with high-performance liquid chromatography by taking advantage of the greater reliability and repeatability of this technique, as well as of the possibility of making the separation automatic. The paper describes how to perform the analysis and the statistical test that was carried out; furthermore a comparison has been made with the usual method and results are in good agreement.
Authors Williams M; Sánchez J; Hann AC; Harwood JL
Title Lipid Biosynthesis in Olive Cultures
Journal Journal of Experimental Botany, 44, 1717-1723
Keywords callus culture; lipid synthesis; Olea europaea L; triacylglycerol;
Abstract Differentiation in olive callus culturad was induce by changing the plant growth regulator content; particulary 2,4-dichloro-phenoxyacetic acid, in the growth media at 25ºC. These cultures have been maintained for an extended period with low polyploid nuclei levels. Analysis of olive callus cultures indicate that the acyl lipid composition varied according to the state of differentiation and to incubation temperature. Heterotrophic olive callus was characterized by its ability to accumulate triacylglycerol rich in oleate, a situation comparable to developing olive fruit. In fact, oleate-rich triacylglycerol was enhanced in heterotrophic callus culturad at 35ºC. Greening calli, however, were noticeably found to posses typical chloroplastic lipids, indicating the presence of intracellular chloroplastic structures, which was confirmed by electron microscopy. These cultures also exhibited acyl compositions wit increased amounts of linoleate and &linolenate, particulary in chloroplastic lipids and a corresponding decrease in oleate and stearate. In this study we have shown that olive callus in various stages of differentiation can be cultured by manipulating the plant growth regulator concentration in the growth media. Such morphological changes were further reflected by alterations in acyl lipid composition. These cultures have remained viable for extended periods and, therefore, appear to be suitable for further investigations of the regulation of lipid formation.
Authors Gigliotti C; Daghetta A; Sidoli A
Title Studio della composizione trigliceridica di oli di semi ad alto contenuto di acido oleico
Journal Rivista Italiana delle Sostanze Grasse, 70, 533-539
Keywords acid oleic; olive oil; triglyceride;
Abstract The results of a study carried out to compare data on acidic; triglyceride and sterolic compositions between olive oils and seed oils with a high oleic acid content (hazel-nut, almond, modified sunflower) either unrefined or refined and in case of desterolized are reported. The difference in the compositions which are of little entity, do not permit to show the possible mixtures between the olive and the seed oils. We do not exclude that for some difference typical of the different species studied, a correlation with other compositive parameters could give useful indications for the recognition of possible mixtures.
Authors Alonso-García MV; Aparicio López R
Title Characterization of European virgin olive oils using fatty acids
Journal Grasas y Aceites, 44, 18-24
Keywords discriminant analysis; fatty acid; Sexia expert system; theory of evidence; Virgin olive oil (characterization);
Abstract The possibility of discriminating between extra virgin olive oils from different regions of Spain; Italy and Portugal by means of their fatty acid content, has been investigated. A dendrogram allowed discrimination between the oils starting from their initial grouping and progressing to differentiation on the basis of regions. Multivariant statistical analyses were applied to determine the actual discriminatory capacity of this group of compounds. The confidence associated with the final discrimination was ascertained using the theory of evidence.
Authors Zupan J; Novic M; Li X; Gasteiger J
Title Classification of multicomponent analytical data of olive oils using different neural networks
Journal Analytica Chimica Acta, 292, 219-234
Keywords multicomponents analysis; neural networks; olive oils;
Abstract A comparison of classification abilities of two different neural network; namely, back-propagation of error and Kohonen learning is made and discussed. The classifications is performed on set of 572 Italian olive oils on the basis of an analysis of eight fatty acids. The comparison of methods is carried out by different neural network architectures for each learning strategy separately. It was found that for the applied classification problem Kohonen neural network can be exploited to give more detailed information about the separation ability of each individual variable, i.e. of each individual fatty acid in our case.
Authors Uceda Ojeda M; Hermoso Fernández M; González Delgado J
Title Elaboración de aceite de oliva con sistemas continuos de dos fases
Journal Alcuza, 19-29
Keywords Olive oil;
Authors Bianchi G; Tava A; Vlahov G; Pozzi N
Title Chemical Structure of Long-Chain Esters from 'Sansa' Olive Oil
Journal Journal of the American Oil Chemists Society, 71, 365-369
Keywords Benzyl alcohol esters; GC-MS; long-chain aliphatic esters; olive oil; olive oil wax esters;
Abstract The major objective of this study was to determine the chemical structure of long-chain esters present in lower-grade olive oil. The classes of esters composing the hexane-diethyl ether (99:1) extract of the wax fraction from a pomace olive oil were:(i) esters of oleic acid with C1-C6 alcohols (ii) esters of oleic acid with long-chain aliphatic alcohols in the range C22-C28 and (iii) benzyl alcohol esters of the very long-chain saturated fatty acids C26 and C28.The analysis and the structure assignments were carried out by gas chromatography coupled with mass spectrometry and by comparison with synthetic authentic model compounds. This work provided precise data on the chemical nature of the wax esters present in olive oil and should represent a means to detect adulteration of higher-grade olive oil with less expensive pomace olive oil and seed oils.
Authors Lanzón A; Albi T; Cert A; Gracián J
Title The Hydrocarbon Fraction of Virgin Olive Oil and Changes Resulting from Refining
Journal Journal of the American Oil Chemists Society, 71, 285-291
Keywords hydrocarbons; refining; Virgin olive oil;
Abstract In numerous Spanish virgin olive oil; 6,10-dimethyl-1undecene, various sesquiterpenes, the series of n-alkanes from C14 to C35, n-8-heptadecene and squalene are the only less volatile components detected by gas chromatography in the hydrocarbon fraction. In oils from olives of the Arbequine variety, a series of n-9-alkanes has also been found. In refined oils, notable features are the absence of the most volatile compounds and the appearance of other hydrocarbons produced during the refining process. Among these, n-alkanes, alkadienes (mainly n-hexacosadiene), stigmasta-3,5-diene, isomerization products of squalene, isoprenoidal polyolefins coming from hydroxy derivatives of squalene and steroidal hydrocarbons derived from 24-methylene cycloartanol were identified. Physical refining produces larger amounts of degradation products and greater losses of n-alkanes than chemical processing. Squalene is the major hydrocarbon component in all oils, both virgin and refined. The ranges of concentration for the different hydrocarbons found in Spanish virgin olive oils are presented.
Authors Van de Voort FR; Ismail AA; Sedman J; Dubois J; Nicodemo T
Title The Determination of Peroxide Value by Fourier Transform Infrared Spectroscopy
Journal Journal of the American Oil Chemists Society, 71, 921-926
Keywords FTIR; hydroperoxide; lipid oxidation;
Abstract A rapid method for the quantitative determination of peroxide value (PV) of vegetable oils by Fourier transform infrared (FTIR) transmission spectroscopy is described. Calibration standards were prepared by the addition of butyl hydroperoxide to a series of vegetable oils; along with random amounts of oleic acid and water. Additional standards were derived through the addition of mono-and diglyceride spectral contributions, as well as zero PV spectra obtained from deuterated oils. A partial least square /PLS) calibration model for the prediction of PV was developed based on the spectral range 3750-3150 cm-1 Validation of the method was carried out by comparing the P V of a series of vegetable oils predicted by the PLS model to the values obtained by the American Oil Chemists, Society iodometric method. The reproducibility of the chemical method. The method, as structured; makes use of a 1-mm CF2 flow cell to allow rapid sample by aspiration. The spectrometer was preprogrammed in Visual Basic to guide the operator in performing the analysis so that no knowledge of FTIR spectroscopy is required to implement the method. The method would be suitable for PV determinations in the edible oil industry and takes an average of three minutes per sample.
Authors Zamora R; Navarro JL; Hidalgo FJ
Title Identification and Classification of Olive Oils by High-Resolution 13C Nuclear Magnetic Resonance
Journal Journal of the American Oil Chemists Society, 71, 361-364
Keywords artificial neural networks; high-resolution 13C NMR; oil quality; olive oil; Pattern recognition; stepwise discriminant analysis; unsaponifiable matter;
Abstract Unsaponifiable matter from 19 olive and olive pomace oils were studied by high-resolution 13C nuclear magnetic resonance spectroscopy. Their spectra showed characteristic peaks that corresponded to molecular substructures rather than the individual constituents present in the unsaponifiable matter. The presence of squalene and other hydrocarbons; sterols and triterpenic alcohols, in addition to other groups of minor compounds, were observed. Based on the analysis of these spectra, it was possible to distinguish among different grades of olive oils by using stepwise discriminant analysis. This direct method of analysis is suggested to be used in artificial neural networks to define oil identity and quality.
Authors Lercker G; Frega N; Bocci F; Servidio G
Title 'Veiled' Extra-Virgin Olive Oils: Dispersion Response Related to Oil Quality
Journal Journal of the American Oil Chemists Society, 71, 657-658
Keywords cloudy oil stability; extra virgin olive oil; natural antioxidant; natural buffer;
Abstract A cloudy ('veiled') extra-virgin olive oil was stored 10 month at room temperature and monitored at 15-d intervals. The oil was very stable under oxidizing conditions; a slight increase in free acidity (from 0.2 to 0.3%; expressed as oleic acid), a notable rise in the amount of diacylglycerols and a minor increase in peroxide content were observed. Turbidity disappeared after a few months due to chemical bonding between a nitrogen-containing component and the free acids that were released over time. The material in suspension, therefore, contained some chemical groups capable of acting as antioxidants.
Authors Li-Chan E
Title Developments in the detection of adulteration of olive oil
Journal Trends in Food Science and Technology, 5, 3-11
Keywords Adulterations of olive oil;
Abstract The authenticity of products labeled as olive oil is of great importance from the standpoints of both commercial value and health aspects. Over the years; a high degree of sophistication has involved in chromatographic methods for the analysis of both major and minor components of oils and fats. At the same time, spectroscopic methods are emerging as potential tools for rapid screening of samples for the detection of adulteration. However, the complexity and intrinsic variability of biological samples such as olive oil and its potential adulterants demands the application of multivariate calibration or pattern-recognition techniques to aid interpretation of the data obtained using these instrumental methods. Combination of the techniques of analytical chemistry and chemometrics is mandatory for unequivocal identification and quantification of the adulteration of olive oil.
Authors Melo J
Title Aceites y grasas... índices de genuidad... índices de calidad
Journal Aceites y Grasas, 3, 75-76
Keywords genuineness; quality;
Authors Aparicio López R; Ferreiro L; Alonso V
Title Effect of climate on the chemical composition of virgin olive oil
Journal Analytica Chimica Acta, 292, 253-241
Keywords altitude; chemometrics; climate; gas chromatography; olive oil;
Abstract The effect of climate on the chemical composition of virgin olive oil has received scant attention. In this work; the relationship between chemical composition and altitude, the latter being an indirect parameter related to climate and soil, was studied. Two altitudes, valley (< 400m) and mountains (> 700 m) were studied; 126 samples of virgin olive oil were characterized by 53 compounds and it was found that sterols and some triterpenic alcohols and hydrocarbons changed systematically with altitude. Two linear discriminant equations, with correct classifications greater than 90%, were obtained and verified with samples of another crop. Similar results were obtained.
Authors Di Giovacchino L; Costantini N; Di Febo M
Title La centrifugazione delle paste di olive senza acqua di diluizione
Journal Rivista Italiana delle Sostanze Grasse, 71, 555-559
Keywords centrifugation; dilution; olive paste;
Abstract The recent introduction in the olive oil extraction process of innovative centrifugal decanters makes possible to separate the oil from the olive paste without the addition of warm water; thereby reducing the quantity of the vegetable water by product. Test were made in two consecutive harvests to measure the impact of the new technology on olive oil extraction yields and on oil quality. A comparison between the new 2- phase and the conventional 3- phase decanter has shown that yields are the same. Moreover, the 2- phase decanter produced about 9 liters of water per 100 kg of olives, and husk containing an average level of 58.0% of water and 3.16% of oil. Finally oils extracted with the two types of decanter have shown significant differences only with respect to the natural antioxidant content and the value of induction time, which are higher in oil extracted with the new 2- phase decanter. Therefore, the new centrifuge produces the following advantages: a reduction in water consumption, thermic energy, and vegetable water disposal cost; an increase in the stability of the oil; the only drawback being an higher moisture content in the husk.
Authors Di Giovacchino L; Solinas M; Miccoli M
Title Aspetti qualitativi e quantitativi delle produzioni olearie ottenute dalla lavorazione delle olive con i differenti sistemi di estrazione
Journal Rivista Italiana delle Sostanze Grasse, 71, 587-594
Abstract Experimental olive oil extraction tests were made in industrial oil mills equipped with pressure and centrifugation plants in the regions of Abruzzo and Apulia. Albeit limited scope; the test results indicate that the two systems under examination help to obtain comparable extraction yields quantifiable, on the average, between 85 and 86%. This is primarily due to the fact that many oil mill operators accelerate the squeezing process and thereby reduce its duration. The resulting increase in the daily working capacity of the oil mill, however, has negative effects on extraction yields. These findings are confirmed by the quantity of oil residue contained in the husk and in the vegetable water respectively measured in 7.7% and 6.7 g/l, using the pressure system, and 4.0% and 12.5 g/l, using the continuous centrifugation system. In addition the analytical determinations show that the two systems have different effects depending on the quality and ripening of the olives. Indeed, with the pressure system, good quality olives have yielded oil with a greater natural antioxidant content (total polyphenols) and, consequently, more stable (Rancimat induction time), while, with the centrifugation system, very ripe and poor quality olives have yielded in general oil with less free fatty acids and, in some instances, oil more acceptable to the taste.
Authors Aparicio López R; Alonso MV; Morales MT; Calvente JJ
Title Relationship between the COI test and other sensory profiles by statistical procedures
Journal Grasas y Aceites, 45, 26-41
Keywords chemometrics; COI test; fuzzy logic; sensory analysis; sensory wheel; Virgin olive oil;
Abstract Relationships between 139 sensory attributes evaluated on 32 samples of virgin olive oil have been analyzed by a statistical sensory wheel that guarantees the objectiveness and prediction of its conclusions concerning the best clusters of attributes: green; bitter-pungent, ripe fruit, fruity, sweet fruit, undesirable attributes and two miscellanies. The procedure allows the sensory notes evaluated for potential consumers of this edible oil from the point of view of its habitual consumers to be understood with special reference to The European Communities Regulation nº2568/91. Five different panels: Spanish, Greek, Italian, Dutch and British, have been used to evaluate the samples. Analysis of the relationships between stimuli perceived by aroma, flavour, smell, mouth feel and taste together with Linear Sensory Profiles based on Fuzzy Logic are provided. A 3-dimensional plot indicates the usefulness of the proposed procedure in the authentication of different varieties of virgin olive oil. An analysis of the volatile compounds responsible for most of the attributes gives weight to the conclusions. Directions which promise to improve the E.C. Regulation on the sensory quality of olive oil are also given.
Authors Morales MT; Aparicio López R; Rios JJ
Title Dynamic headspace gas chromatographic method for determining volatiles in virgin olive oil
Journal Journal of Chromatography, 668, 455-462
Keywords volatiles; gas chromatographic; dynamic headspace; Virgin olive oil;
Abstract Dynamic headspace sampling methods prior to capillary gas chromatography are especially suitable in the determination of volatile compounds at a wide range of concentrations; and numerous methods have been developed and applied to very different kinds of samples. In this work, a simple and rapid dynamic headspace technique was developed to determine volatiles present in virgin olive oil samples. Headspace components were swept from 0.5 g of sample at low temperature (40°C) and concentrated on Tenax TA, thermally desorbed and subsequently trapped in a fused-silica cold trap previously cooled to -110°C. They then passed to the capillary column. This system was connected to a mass spectrometer to identify the most important compounds and a comparative study of the main volatiles identified in virgin olive oil samples using other methods was carried out. Sniffing of the components eluted from the chromatographic column was also performed. Different virgin olive oil samples showing different chromatographic profiles were analyzed. The differences were mainly quantitative because most compounds were present in all oils analyzed, and only the proportions in which these compounds are present varied. Discriminant analysis of these compounds allowed the origin of each sample to be determined with a probability of greater than 90%.
Authors Osman M; Metzidakis I; Gerasopoulos D; Kiritsakis AK
Title Qualitative changes in olive oil of fruits collected from trees grown at two altitudes
Journal Rivista Italiana delle Sostanze Grasse, 71, 187-190
Keywords olive oil;
Abstract Olive fruit exhibits a sigmoid growth curve (18); and the oil which appears early in the pulp parenchyma between the end of July and beginning of August, increases gradually throughout fall and reaches a maximum in late December (12). Borbolla et al. (15), has reported that the average weight, mean and flesh to pit ratio increased steadily throughout growth and maturation. Fruisture loss paralleled a progressive increase in oil. Oil content increases during the growing season (14), and soluble sugars, decline up to maturity after a brief rise. The cultivar determines the fruit characteristic after a brief rise. The cultivar determines the fruit characteristics as well as the chemical composition of the oil (1).
Titratable acidity, one of the basic criteria for olive oil grading, Increases progressively with fruit maturity (2,6) through the activity of endogenous lipase enzymes, or if the fruit remains longer on the colleting nets from both endogenous and microbial lipases (4). Olive fruit phenols are water-soluble, and small quantities are present in oil, increasing its oxidative stability (10). The polyphenol content in olive oil depends on agronomic factors (16) and oil extraction methods (13). Polyphenols extracted from olive leaves have been reported to act as antioxidants when added to olive oil (11). An increase in unsaturated fatty acids, one of the main changes in oil composition, along with the process of fruit maturation has also been reported (9), Within the growing area, the percentage of unsaturated fatted fatty acids increases when the temperature is low (5); consequently olives from cold areas produce oil with more unsaturated fatty acid compared to dry and warm areas. The purpose of this study is to investigate the qualitative changes in olive oil fruit obtained from trees grown at 100m and at 400m altitude.
Authors Pallotta U
Title A Review of Italian Research on the Genuineness and Quality of Extra Virgin Olive Oil
Journal Italian Journal of Food Science, 3, 259-274
Keywords methods of analysis; olive oil; quality control;
Abstract L'olio di oliva extra vergine italiano; fra gli oli di oliva del commercio, ha requisiti organolettici, merciologigi e nutrizionali molto pregiati. Per la composizione trigliceridica e della frazione insaponificabili è un alimento di elevato valore biologico che integra e valorizza il pregio della 'diete mediterranea'. Il suo impiego nell'alimentazione umana merita quindi di essere semper più valorizzato e diffuso. Si ottiene, come è noto, per spremitura meccanica delle olive sane (con frantoi a sistema continuo centrifugo e discontinuo a pressa) seguita da lavaggio, decantazione, centrifugazione e filtrazione: coè con soli metodi fisici a freddo. La difesa e la certificazione della qualità e della genuità di questa categoria di oli di oliva è oggi assiuratta dai vigemti Regolamenti CEE che prescrivono una serie di parametri fisico-chimici, chimici e sensoriali capaci di definire esaurientemente degli 'standard' di qualità e di genuinità. È sufficiente che uno solo dei parametri non sia conforme al valore stabilito perché l'olio sia declassato di qualitá o dichierato non genuino. I Regolamenti CEE, entrati in vigore, ed a limiti proposti dal COI, rappresentano una maggiore sicurezza e garanzia per i consumatori, se si confrontano con quanto pescritto dalla passata legislazione italiana. Un'ulteriore garanzia ed una tutela più articolata del consumatore potrà essere raggiunta in un prossimo futuro, perché questi Regolamenti prevedono degli aggiornamenti ai metodi analiciti o la revisione dei limiti prescritti o l'introduzione di altri metodi per poter effettuare ulteriori,significativi controlli.
Authors Aparicio López R; Alonso V; Morales MT
Title Detailed and exhaustive study of the authentication of European virgin olive oils by SEXIA expert system
Journal Grasas y Aceites, 45, 241-252
Keywords authentication; olive oil; Sexia expert systems; statistics;
Abstract The authentication of extra virgin olive oils from different regions of Spain; Italy and Portugal, by means of their fatty acids, alcohols, sterols, methyl sterols and hydrocarbons content, has been investigated. Multivariate statistical methods and Evidence's Theory were applied. The comparative study shows greater predictive ability using this theory than the traditional statistical methods or expert systems that do not implement the possibility theory. A detailed and exhaustive study of Italian (Tuscany and Basilicata), Portuguese and Spanish virgin olive oils has been made. Geographically colored maps of the studied regions are shown to strengthen the numerical results.
Authors Inglese P
Title La influencia de la variedad en las características cualitativas del aceite de oliva
Journal Olivæ, 54, 42-47
Keywords olive oil;
Authors Di Giovacchino L; Solinas M; Miccoli M
Title Effect of Extraction Systems on the Quality of Virgin Olive Oil
Journal Journal of the American Oil Chemists Society, 71, 1189-1194
Keywords o-diphenols; olive oil; extraction systems; quality; polyphenols;
Abstract Research has been carried out top ascertain the effects of different processing systems on olive oil quality. Tests were performed in industrial oil mills that were equipped with both pressure and centrifugation systems. Results show that oils extracted from good- quality olives do not differ in free fatty acids; peroxide value, ultraviolet absorption and organoleptic properties. Polyphenols and o- diphenols contents and induction times are higher in oils obtained from good - quality olives by the pressure system because it does not require addition of water to the olive paste. The centrifugation system requires the addition of warm water to the olive paste and helps to obtain oils with a lower content of natural antioxidants. Oils obtained from poor-quality or from ripe olives in continuous centrifugal plants are lower in free fatty acids than those obtained by the pressure system.
Authors Grob K; Bronz M
Title Analytical problems in determining 3,5-stigmastadiene and campestadiene in edible oils
Journal Rivista Italiana delle Sostanze Grasse, 71, 291-295
Keywords 3,5-stigmastadiene; edible oils;
Abstract GC on polar capillary columns does not resolve the 2;4-isomer from the 3,5-stigmastadiene. Results obtained by the commonly used methods are, therefore, 10-30% too high. Separation of these isomers is possible on Carbowax-type stationary phases Accurate determination of campestadiene in olive oil is jampered by disturbing squalene isomerization products and another, unknown component. High resolution preseparation by HPLC removes the former, but not the latter.
Authors León Camacho M; Cert Ventulá A
Title Recomendaciones para la aplicación de algunos métodos analíticos incluidos en el reglamento CEE 2568/91 relativo a las características de los aceites de oliva y de orujo de oliva
Journal Grasas y Aceites, 45, 395-401
Keywords olive oil; olive pomace oil; sterol (determination); trans isomer (determination); trilinolein (determination); wax (determination);
Abstract Among the analytical methods officially adopted by the European Union to be applied to olive pomace oils and olive oils; some troubles have been found in the application of the procedures for the determination of sterols, trilinolein, trans isomers of fatty acids and waxes. The study of such difficulties suggests several modifications and recommendations facilitating the performance of methods and improving the reliability of results.
Authors Mag TK
Title How processing has improved oil quality
Journal Inform, 5, 926-931
Keywords oil quality; processing;
Authors Grob K; Giuffrè AM; Leuzzi U; Mincione B
Title Recognition of Adulterated Oils by Direct Analysis of the Minor Components
Journal Fatty Science Technology, 96, 286-290
Keywords oils; analysis; Adulteration;
Abstract Recognition of adulteration by other oils via direct analysis of the minor components (' sterols fraction ') is shown for olive oil. 10% of various oils were admixed; the free alcohols silylated and the minor components analyzed by on-line coupled LC- GC- FID. For most oils, even smaller additions can be recognized. Admixed oils can no longer be determined, however, if their minor components have been removed by strong raffination. Bleaching of rapeseed oil with 7% of earth at 180ºC, in fact, completely removed free and esterified sterols.
Authors Blekas G; Tsimidou M; Boskou D
Title Contribution of a-tocopherol to olive oil stability
Journal Food Chemistry, 52, 289-293
Abstract The effect of 100;500 and 1000 ppm of a-tocopherol on the oxidative stability of purified olive oil kept in the dark at 40ºC was studied. Purified olive oil was prepared by liquid column chromatography and was practically devoid of minor constituents with possible pro-oxidant or antioxidant activity. a-Tocopherol acted as antioxidant at all levels of addition, although the antioxidant effect was greater at 100 ppm than at higher concentrations. In the initial stage of autoxidation a slightly pro-oxidant effect was observed. In the presence of strong antioxidants naturally occurring in olive oil, such as ortho-diphenols, a-tocopherol did not show any significant additional antioxidant effect during the period of low peroxide accumulation.
Authors Martín-Polvillo M; Albi T; Guinda A
Title Determination of Trace Elements in Edible Vegetable Oils by Atomic Absorption
Journal Journal of the American Oil Chemists Society, 71, 347-353
Keywords atomic absorption spectroscopy; graphite furnace; trace metals; vegetable oil;
Abstract Methods are described for the direct determination of Al; Cr, Cu, Fe, Ni, and Pb by atomic absorption spectrophotometry in sunflower oil and olive oils. Metallic contamination after storage under different controlled conditions and in contact with carbon steel, austenic steel, ferritic steel and aluminium was examined. Additionally, chemical characteristics related to quality (acid value, peroxide value, K270 and oxidative stability) and some physical parameters of interest were evaluated after storage. When the samples were atomized directly off the tube wall, matrix interferences were not observed in the determination of Cr, Cu, Ni and Pb, whereas such interferences were noted when Al and Fe were determined. The results indicated that the L' Vov platform for Al and Fe determinations eliminates the matrix effects. Contamination with Fe was only detected in the olive oil that had been in contact with carbon steel, Fe concentration increased from 120 ± 12 to 3.520 ± 157 ppb. The physicochemical characteristics were affected only by the storage conditions, regardless of the metal sheets with which they were in contact. Virgin olive oil showed lowered stability after storage in contact with a carbon-steel sheet than when stored in absence of metal.
Authors Lai YW; Kemsley EK; Wilson RH
Title Potential of Fourier Transform Infrared Spectroscopy for the Authentication of Vegetable Oils
Journal Journal of Agricultural and Food Chemistry, 42, 1154-1159
Keywords vegetable oils; FTIR; authentication;
Abstract Fourier transform infrared (FTIR) spectroscopy was used in conjunction with principal component analysis (PCA) and discriminant analysis to investigated the potential of the technique for determining the authenticity vegetable oils. PCA applied to spectra from a range of seed oils revealed clustering according top plant species. When extra virgin and refined olive oils were subjected to discriminant analysis; 93% of samples in a calibration set and 100% of samples in an independent validation set were correctly classified, despite these two types of oil being chemically and spectroscopically very similar. The method, therefore, has potential as a rapid method for the determination of product authenticity.
Authors Drava G; Forina M; Lanteri S; Lupoli M
Title Development of the chemical model of a typical food product: olive oil from an Italian region (Basilicata)
Journal Journal of the Science of Food and Agriculture, 65, 21-30
Keywords chemometrics; class-modelling; olive oil;
Abstract Samples (158) of olive oil produced in an Italian region (Basilicata) and described by 52 chemical variables were analyzed together with samples of different geographical origin using chemometric techniques. After selection of the variables discriminating best between the samples from Basilicata and those from the reference regions; two homogeneous zones of Basilicata were studied in detail: several class-modelling methods were applied in order to build the models of the oil produced in those areas. Compact models of the northern and central areas of Basilicata were obtained with a variance comparable to the models of well-characterized regions of oil production.
Authors Van de Voort FR; Ismail AA; Sedman J
Title A Rapid Automated Method for the Determination of cis and trans Content of Fats and Oils by Fourier Transform Infrared Spectroscopy
Journal Journal of the American Oil Chemists Society, 72, 873-880
Keywords FTIR spectroscopy; lipid analysis; cis trans analysis;
Abstract A rapid Fourier transform infrared (FTIR) method was developed to simultaneously determine percent cis and trans content of edible fats and oils. A generalized; industrial sample- handling platfor/accessory was designed for handling both fats and oils and was incorporated into an FTIR spectrometer. The system was calibrated to predict the cis and trans content of edible oils by using pure triglycerides as standards an partial least square as the chemometric approach. The efficacy of the calibration was assessed by triglyceride standard addition, by mixing of oils with varying cis/trans contents, and by analyzing fats and oils of known iodine value. Each of the approaches verified that the FTIR method measured the cis and trans content in a reproducible (+/-0.7%) manner, with the measured accuracies being 1.5% for standard addition and 2.5% for the chemically analyzed samples. Comparisons also were made to the conventional American Oil Chemists, Society (AOCS) method for the determination of trans isomers by IR spectroscopy. The FTIR -partial least squares approach worked well over a wide range of trans contents, including those between 0 and 15%. The sample-handling accessory designed for this application is robust, flexible, and easy to use being particulary suited for quality-control applications. In addition, the analysis was automated by programming the spectromer in Visual Basic (Windows), to provide a simple, prompt-based user interface and to allow an operator to carry out cis/trans analysis requires less than two minutes per sample. The derived calibration is transferable between instruments eliminating the need for recalibration. The integrated analytical system provides a sound basis for the implementation of FTIR methods in place of variety of AOCS wet chemical methods when analytical speed, cost, and environmental concerns issues.
Authors Brühl L; Fiebig HJ
Title Qualitätsmerkmale Kaltgepreßter Speiseöle
Journal Fatty Science Technology, 97, 203-208
Abstract The determination of steradienes; trans fatty acids and free fatty acids together with the UV absorption at 232 and 270 nm leads to quality characteristics for cold pressed edible oils.Two methods, GLC and a HPLC method, are both valid for the determination of steradienes. In addition with the determination of trans fatty acids they are a powerful tool for the determination of adulterations of cold pressed native edible oils with refined oils. The amount of free fatty acids and the UV absorption provide only ambiguous information for the characterization of cold pressed oils.
Authors Moreda W; Pérez Camino MC; Cert Ventulá A
Title Determinación de algunos parámetros de pureza en aceites de oliva. Resultados de un estudio colaborativo
Journal Grasas y Aceites, 46, 279-284
Keywords Collaborative study; olive oil; Purity parameter; statistical analysis;
Abstract The results of a collaborative study with the participation of Governmental and Olive Oil Industry laboratories is presented. This study was carried out to determine the precision of the analytical methods used for quantifying certain components of olive oils. Samples of virgin olive oil; olive oil and residue olive oil were analyzed for total sterols, sterolic composition, trans isomers from fatty acids, waxes and stigmastadienes, using the analytical methods included in the Commission Regulation EEC 2568/91 of the European Union and modifications therein, and in Document TC20/11 of the International Olive Oil Council (1993). The results have been statistically processed according to the standard ISO 5725-1986(E).
Authors Di Giovacchino L; Serraiocco A
Title Influenza dei sistemi di lavorazione delle olive sulla composizione dello spazio di testa degli oli
Journal Rivista Italiana delle Sostanze Grasse, 72, 443-450
Abstract A research was carried out to evaluate the impact of different working systems on the chemical composition of the headspace of olive oil. Tests were made in industrial oil mills equipped with pressure and centrifugation plants. Results show that; in processing good quality olives, centrifugation system helps to obtain oil with a lower content of n-octane, of iso-amyl alcohol, of iso-butyl alcohol and of acetic acid, that are responsible for flaws like ' fusty ' and ' winey ' taste. Moreover, oil obtained through centrifugation has a more intense green fruity aroma as it contains a higher percentage of t-2-hexenal with respect to total aromatic substances. While, with poor quality olives, pressure system produces oil with flaws (like ' fusty ' and ' winey ' taste) due to the presence in high concentration of n-octane, iso-amyl alcohol, iso-butyl alcohol, acetic acid and ethyl acetate which originate from the fermentation of the olive paste residue that accumulates on filtering diaphragms. On the contrary, oil obtained through centrifugation is of better quality since it has a significantly lower content of the aforementioned substances. This is so because centrifugation plants are built in easily washable stainless steel that eliminates the risk of oil contamination.
Authors Fernández-Bolaños J; Rodríguez R; Guillén R; Jiménez A; Heredia A
Title Activity of cell Wall-Associated Enzymes in Ripening Olive Fruit
Journal Physiologia Plantarum, 93, 651-658
Keywords Cell wall; endoglucanases; glycosidases; Olea europaea; olive fruit; polygalacturonases; ripening; softening;
Abstract Enzimatically active cell wall isolated from olive (Olea europaea) fruit was employed to investigate some hydrolytic enzymes bound to the cell wall and the changes in these during ripening. Seven glycosidases b-glucosidase (EC 18.104.22.168); b-galactosidase (EC 22.214.171.124), a-arabinosidase (EC 126.96.36.199), a-mannosidase (EC 188.8.131.52), b-xylosidase (EC 184.108.40.206) and b-N-acetylglucosaminidase (EC 220.127.116.11), as well as Cx-cellulase (EC 18.104.22.168) and endo-polygalacturonase (EC 22.214.171.124), were identified in the cell wall preparation, at four stages of ripeness (mature green, changing color, black and black-ripe). Activities of all these cell wall-associated enzymes (ionically and covalently linked) were determined either by cell wall incubation with artificial substrate or after extraction from the cell wall with buffers of high salt concentration (Cx-cellulase), and were compared to those of forms solubilized from acetone powders with 500 mM citrate buffer (cytoplasmic and/or apoplastic plus ionically bound to cell wall). In general, the activities of low ionic strength buffer-soluble enzymes were found to be much higher than those of the bound enzymes. The bound enzymes are present in the fruit at the green color stage, whereas the activities of the soluble enzymes only increased from the changing color stage onwards. The tenacity of binding of enzymes to the wall was investigated by treating the walls with high salt and measuring residual activity. The nature of the ionic and covalent binding and the changes during ripening were also established for wall-bound glycosidase. During ripening there was a marked change in the percentages of covalenty-and ionically linked activities of b-glucosidase and b-galactosidase; at the changing color stages about 75-80% of the bound activity was present in high ionic strength buffer while at the black-ripe stage it was only 15-20%. A possible role for these cell wall degradative enzymes in olive softening is discussed.
Authors Dionisi F; Prodolliet J; Tagliaferri E
Title Assessment of Olive Oil Adulteration by Reversed-Phase High-Performance Liquid Chromatography/Amperometric Detection of Tocopherols and Tocotrienols
Journal Journal of the American Oil Chemists Society, 72, 1505-1511
Keywords Adulteration; HPLC; olive oil; tocopherols; tocotrienols; vegetable oils;
Abstract A method involving reversed -phase high- performance liquid chromatography with amperometric detection has been developed for the analysis of tocopherols and tocotrienols in vegetable oils. The sample preparation avoids saponification. Recoveries of a - tocotrienol and g - tocotrienol in extra virgin olive oil were 97.0 and 102.0 %; respectively. No tocotrienols were detected in olive, hazelnut, sunflower, and soybean oils, whether virgin or refined. However, relatively high levels of tocotrienols were found in palm and grapeseed oils. This method could detect small quantities (1-2%) of palm and grapeseed oils in olive oil or in any tocotrienol-free vegetable oil and might, therefore, help asses authenticity of vegetable oils.
Authors Jiménez Márquez A; Hermoso Fernández M; Uceda Ojeda M
Title Elaboración del aceite de oliva virgen mediante sistema continuo en dos fases. Influencia de diferentes variables del proceso en algunos parámetros relacionados con la calidad del aceite
Journal Grasas y Aceites, 46, 299-303
Keywords Process variables (influence of); Quality parameter; two-phase continuous system; virgin olive oil (extraction);
Abstract Con la implantación; en el sector de la elaboración del aceite de oliva virgen, de nuevos avances tecnológicos, se hace necesario el conocimiento de cómo puede afectar a determinados parámetros del aceite obtenido las diferentes formas de conducir el proceso. Se estudia la respuesta de los polifenoles totales, amargor y estabilidad frente a la oxidación, respecto a las variaciones de temperatura, tiempo de batido, ritmo de producción y lavado del aceite en centrifugas verticales, en un sistema de dos fases en el que no se emplea agua de dilución de masa en la inyección de esta al decanter. Se observa que batiendo la masa a temperaturas bajas, prolongando el batido, y en consecuencia a ritmos lentos, y cuanto mayor es la temperatura y cantidad de agua en el lavado, el aceite obtenido es de menor estabilidad, de contenido más bajo en polifenoles y menos amargo.
Authors Frega N; Mozzon M; Servidio G
Title Studio della resistenza all´ossidazione forzata degli oli extra vergini mediante Rancimat Test
Journal Rivista Italiana delle Sostanze Grasse, 72, 493-496
Keywords extra virgin olive oil; HRGC; oxidative stability; polyphenolic fraction; racimant test;
Abstract e' stato studiato il comportamento all'ossidazione forzata; mediante Racimat Test, dell'olio extra virgine di oliva ottenuto con tre diversi sistemi tecnologici di estrazione. Le prove cerso l'ossidazione forzata hanno riguardato anche un oliom raffinato, un olio extra vergine privato della frazione polifenolica e di quest'ultimo trattatocon porcentuali crescendti di terre decoloranti. Inoltre sono stati studiati mediante gas-cromatografia (HRGC) i componenti altobollenti della frazione polifenolica estratta da un olio extra vergine e da un olio di oliva reffinato. Viene confermato il potere antiossidante della frazione polifenolica estratta dall'olio extra vergine. Gli oli estratti con i diversi sistemi tecnologici mostrano tempi di induzione diversi. Tra i componenti altobollenti della frazione polifenolica dell'olio extra vergine sono stati riscontrati, l'acido oleanoloico, l'acido maslinico, gli isomeri 1-e 3-monoacilgliceroli e i 2-monoacilgliceroli a19 e 21 atomi de carbonio, oltre ad una serie di altri componenti non identificati. negli oli raffinati i componenti altobollenti sono rappresentati pressoché esclusivamente da monoacilgliceroli.
Authors Montedoro GF; Servili M; Baldioli M; Selvaggini R; Perretti G; Magnarini C; Cossignani L;
Title Characterization of some Italian virgin olive oils in relation to origin area
Journal Rivista Italiana delle Sostanze Grasse, 72, 403-414
Keywords Characterization; olive; origin;
Abstract Samples of virgin olive oils produced in different geographical areas of Italy and in different years were analyzed by instrumental analysis. Sixty-one analytical parameters were analyzed; principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA) was used to classify the samples in relation to area of origin. Four clusters corresponding to four different areas of production were defined. PCA applied to the samples for each cluster showed the discrimination of samples in relation to the year of production and the micro climatic conditions present in the same geographic area. The loadings and the discriminating powers calculated for each analytical parameter showed an important effect in the discrimination of clusters for the phenolic compounds, the aroma compounds, the fatty acid composition and the triacylglycerols.
Authors El-Hamdy AH; El-Fizga NK
Title Detection of olive oil adulteration by measuring its authenticity factor using reversed-phase high-performance liquid chromatographic
Journal Journal of Chromatography, 708, 351-355
Keywords olive oil; Adulteration; authenticity; liquid chromatographic; HPLC;
Abstract Addition of as little as 1% of linoleic -rich vegetable oils to olive oil can be detected easily and quantitatively by reversed-phase high- performance liquid chromatography on an octyl-bonded silica stationary phase (Supelcosil-LC 8).The mobile phase was acetone- acetonitrile (70 : 30; v / v), used isocratically. The chromatogram of pure olive oil was compared with those of mixtures of soybean, sunflower and corn oils with olive oil. The results indicate the possibility of the detection of adulteration by less than 1% of linoleic-rich vegetable oils in olive oil qualitatively and quantitatively in less than 15 min. An olive oil authenticity factor was established as a rapid indicator of adulteration and a simple equation for determining the extent of adulteration was derived.
Authors Gomes T
Title A Survey of the Amounts of Oxidized Triglycerides and Triglyceride Dimers in Virgin and 'Lampante' Olive Oils
Journal Fatty Science Technology, 97, 368-372
Keywords oxidized triglycerides; triglyceride dimers; Virgin olive oil; 'lampante' olive oil;
Abstract The aim of this work was to ascertain the amount of oxidized triglyceride dimers in virgin and 'lampante' olive oils: to this effect. 38 samples were collected from different oil-mills. No data on the above compound classes in 'lampante' olive oils have ever appeared in literature up to now. However; fat autoxidation is known to imply polymerization reactions: so, low amounts of oligopolymers may be formed in oil at a given state of oxidation. This aspect also applies to virgin olive oils because the very few data reported in literature are mainly related to extra virgin olive oils which are classified as high quality oils. Column chromatography and high-performance size exclusion chromatography were used for oil analysis in this work. Triglyceride dimers were either absent or present in traces in virgin olive oils, but were found in 'lampante' oils with a mean value of 0.07%. Oxidized triglyceride percentages in 'lampante' oils were more than twice as high as those present in virgin oils. The data obtained suggest the following consideration: the presence of dimers in vegetable oils reveals a rather high oxidation level and is confirmed by the higher oxidized triglyceride values. This is a reliable index of oxidative degradation in oil.
Authors Morales MT; Alonso MV; Aparicio López R
Title Virgin Olive Oil Aroma: Relationship between Volatile Compounds and Sensory Attribute by Chemometrics
Journal Journal of Agricultural and Food Chemistry, 43, 2925-2931
Keywords Flavor; olive oil; sensory analysis; statistics; volatiles;
Abstract Volatile compounds are responsible for virgin olive oil aroma; and this paper demonstrates that basic sensory perceptions (green, fruity, sweet, ripe, over-ripe, undesirable, pungent) can be totally explained by volatile compounds with R2-adjusted < 0.85. Thirty two samples of 6 european varieties of virgin olive oil were characterized by 55 chemical compounds and 55 sensory attributes evaluated by 6 different panels of the United kingdom, Spain, The Netherlands, Greece, and Italy. Multidimensional scaling was used to bring out inter-intra dissimilarities from datasets of sensory attributes and volatile compounds.
Authors Synouri S; Frangisco E; Christopoulou E; Lazaraki M; Alexiou F
Title Influence of certain factors on the composition of olive-pomace oils. Part I: triglycerides and fatty
Journal Rivista Italiana delle Sostanze Grasse, 72, 483-491
Keywords acids; Composition; Factor; fatty acid; oil; oils; olive pomace oil; triglycerides;
Abstract Statistical data on the composition of 53 samples of Greek olive-pomace oil shows that the values of trilinolein (mean 0,72) and differences between theoretical and experimental values of ECN42 (mean 0,64) exceed the limits defined in Regulation EEC 2568/91 and the IOOC Trade Standard. These deviations also exist after treatment of the olive-pomace oils with the cartridge procedure.
In view of the importance of these deviations in the trading of olive-pomace oils, we tried to investigate the reasons underlying the high values of LLL, ECN42 and ECN42 differences observed. Samples of two varieties of olives were selected (Koroneiki and Kolovi) and the composition of the respective olive oils, olive-stone oils and olive-pomace oils was examined. Olive-stone oils are characterized by higher LLL concentrations than olive oils, the overall triglyceride and fatty acid composition being different. Although the olive oils from the Koroneiki variety have lower concentrations of linoleic acid than those of the Kolovi variety, the inverse occurs with the respective olive-stone oils. Olive-stone oils from the Koroneiki variety exhibit a nearly 2-fold concentration of LLL as compared to the Kolovi olive-stone oils. Differences also exist in the concentrations of OLL, OOO, ECN42, ECN44, ECN46 and ECN48. Moreover, differences between experimental and theoretical values of ECN42 are particularly marked in the Koroneiki olive-stone and olive-pomace samples.
Results demonstrate that the relative contribution of the various parts of the fruit in the olive-pomace has a considerable effect on the composition of the olive-pomace oil and is of major importance for the increased values of LLL and ECN42 differences observed. This is also shown by the fact that olive-pomaces obtained from centrifugal plants result in olive-pomace oils with more intense attributes of the stone oils than those obtained from traditional olive oil mills.
Authors Mariani C; Venturini S; Grob K
Title Individuazione dell´olio di girasole alto oleico desterolato nell´olio d´oliva
Journal Rivista Italiana delle Sostanze Grasse, 72, 473-482
Abstract Adulteration of olive oil with sunflower high oleic oil is determined by D7 sterols analysis. Nevertheless the sterol fraction can be eliminated by extreme conditions rectification process; making the analyses nearly useless. During rectification process D7 sterols, unlike D5 sterols, are not dehydrated but are isomerized to D8(14) and D14 sterols. These sterols, analyzed by the official methods, are coeluted during the gaschromatographic analysis with D5 sterols (24-methylcolesterol and b-sitosterol) making impossible the identification of an eventual addition of sunflower oil to olive oil. In the present work a method is reported allowing the separation of D8(14) and D14 sterols from D5 sterols, making then possible to determine low addition of desteroled sunflower oil in olive oil.
Authors Wesley IJ; Barnes RJ; McGill AEJ
Title Measurement of Adulteration of Olive Oils by Near-Infrared Spectroscopy
Journal Journal of the American Oil Chemists Society, 72, 289-292
Keywords Near-Infrared Spectroscopy; olive oil; principal component analysis;
Abstract Authentication of olive oils of great importance; not only because they command a high price but also because of the health implications of adulteration with seed oils. A method for predicting the level of adulteration in a set of virgin and extra-virgin olive oils adulterated with corn oils, sunflower oil, and raw olive residue oil by near-infrared spectroscopy is presented. The best result was a correct prediction for 98% of the samples. Principal component analysis was used to predict the type of adulterant. The best results it is concluded that it is possible to design a quality control system, which uses near-infrared technology to measure the level of adulteration. in the case where the only test in whether the sample is adulterated or not a simple calibration for adulteration can be used. The results suggest that principal component analysis may offer a means of identifying the adulterant, although more work is required to give an acceptable level of accuracy.
Authors Servili M; Conner JM; Piggott JR; Withers SJ; Paterson A
Title Sensory Characterization of Virgin Olive Oil and Relationship with Headspace Composition
Journal Journal of the Science of Food and Agriculture, 67, 61-70
Keywords flavour; free-choice profiling; odour; partial least squares; volatiles;
Abstract Thirty samples of virgin olive oil were analyzed by sensory and instrumental methods. Free-choice profiling and quantitative descriptive analysis were used for odour analysis; and GC-MS for the analysis of headspace volatiles. Principal component analysis and partial least squares regression analysis were used for relating sensory and instrumental data. Similar cluster of samples were obtained from principal components analyses of both data sets. Partial least squares regression made good predictions from headspace data of some of the descriptor used in quantitative descriptive analysis. The prediction of cut grass odour was obtained in particular from five inidentified compounds. The five compounds had similar mass spectra, But GC-sniffport analysis showed that only one of them (possibly isomers or homologues) gave an aroma that could be related to the cut grass descriptor.
Authors Lai YW; Kemsley EK; Wilson RH
Title Quantitative analysis of potential adulterants of extra virgin olive oil using infrared spectroscopy
Journal Food Chemistry, 53, 95-98
Abstract The determination of food authenticity and the detection of adulteration are problems of increasing importance in the food industry. This is especially so for ' value- added' products; where the potential financial rewards for substitution with a cheaper ingredient are high. In this paper, the potential of infrared spectroscopy as a rapid analytical technique for the quantitative determination of adulterants in extra virgin olive oil is demonstrated. The method uses Fourier transform infrared spectroscopy, combined with attenuated total reflectance and partial least squares regression. Model systems comprising two types of ' contaminant' oil -refined olive and walnut- are investigated.
Authors Van Bruggen PC; Quadt JFA; L' Herminez PC; Vandeginste B
Title Robust Sensory Evaluation of Olive Oil by a Non-parametric Scoring System
Journal Journal of the Science of Food and Agriculture, 67, 53-59
Keywords extra virgin; nine-point scale; olive oil; ordinary virgin; outlier; precision; sensory evaluation; statistics; taster; three-point scale; virgin;
Abstract The quality grade of an olive oil is attributed on the basis a of chemical and physical parameters; and in accordance with EC rules, additionally by the sensory evaluation by a taste panel. evaluation of the statistics of the method of the Conseil Oléicole International (COI) as reported by Albi and Gutierrez (J Sci Food Agric 54 (1991) 255-267) revealed a of limitations and weaknesses. An alternative test has therefore been developed. Oils are first tasted by a small panel which decides on acceptance, rejection or further sensory evaluation by a lager panel. The alternative conceptually simpler nonparametric three-point scoring system developed removes some drawbacks of the CSIC method. The method was applied to the panel results published by Albi and Gutierrez and the results of both methods were compared.
Authors Cortesi N; Azzolini A; Rovellini P; Fedeli E
Title Il componenti minori polari degli oli vergini di oliva: ipotesi di struttura mediante LC-MS
Journal Rivista Italiana delle Sostanze Grasse, 72, 241-251
Keywords LC-MS; Virgin olive oil;
Abstract By coupled LC-MS (APCI) we were able to define most of the chemical structures in a minor polar components fraction of a virgin olive oil and to compare them to HPLC profile at 280 and 240nm. As we had already supposed these MPC are part of glucosidic secoiridoid liposoluble derivatives; like oleoeuropeine, distributed into the oil as aglycons secoiridoid acids and phenilethylic alcohols.
Authors Kubo A; Lunde C; Kubo I
Title Antimicrobial Activity of the Olive Oil Flavor Compounds
Journal Journal of Agricultural and Food Chemistry, 43, 1629-1633
Keywords antimicrobial activity; Olea europaea; α,β-Unsaturated Aldehydes;
Abstract A series of long-chain a-b-unsaturated aldehydes have been characterized as antimicrobial agents from the olive Olea europaea fruit and its oil flavor. These volatile compounds exhibited a broad antimicrobial spectrum.
Authors Biedermann M; Grob K; Mariani C
Title On-Line LC -UV -GC -FID for the determination of Δ7-and Δ8(14) -sterols and its application for the detection of adulterated olive oils
Journal Rivista Italiana delle Sostanze Grasse, 72, 339-344
Abstract A method is described for routine analysis of D7 and D8(14)-stigmastenol in edible oil. It involves transesterification of the oil and on line LC-GC-FID with LC-GC transfer of the fraction of the D7-and D8(14)-sterols guided by UV peak detection. Among 160 olive oils analyzed; D7-stigmastenol concentrations in extra virgin oil never exceeded 7,5 mg/kg nor did the sum of the concentrations of D7-and D8(14) stigmastenol in refined olive oils. 7,5 mg/kg corresponds to 0,5% related to the sterols (EU limit) and a total sterol concentration of 1500 mg/kg. It is, therefore, proposed to consider a limit of 7,5 mg/kg for the sum of the concentrations of D7-and D8(14)- stigmastenol in olive oils. The concentration of D8(14)- stigmastenol should not exceed 2 mg/kg.
Authors Angerosa F; Di Giacinto L
Title Caratteristiche di qualita dell'olio di oliva vergine in relazione ai metodi di frangitura.Nota II
Journal Rivista Italiana delle Sostanze Grasse, 72, 1-4
Keywords evidence; olive; quality; oil;
Abstract In order to evidence the influence of olive crushing system on the quality characteristics of the resulting commodities; the Authors compared oils extracted from homogeneous lots of olive varieties Provenzale and Rotondella by means of a stone mill and a metal disc crusher Alfa-Laval; the olive pastes obtained were processed in the same conditions after the crushing. The quality of resulting oils has evaluated by sensory analysis determination of chemical-physical indices, analysis of natural antioxidants, induction time, dosage of chlorophyll and qualy-quantitative analysis of volatile compounds at 37ºC. The results obtained evidenced that, except for acidity, peroxide index and U.V. spectrophotometric data, that have been very similar, the crushing system influenced the oil quality. Particularly oils with intense bitter taste and feeble fruity, with higher content of chlorophyll and phenolic substances than those resulting by means of a stone mill are extracted by means of metal disc crusher.
Authors Paganuzzi V; De Iorgi F; Malerba A
Title Sull' olio di oliva vergine extra impiegato in conserve alimentari confezionate in contenitore di vetro. Nota 1- Variazione di alcuni parametri chimico-fisici al mutare delle condizioni di produzione e nel corso dell' invecchiamento
Journal Rivista Italiana delle Sostanze Grasse, 72, 529-537
Keywords extra virgin olive oil; Characteristics changes; disqualification; ageing;
Abstract Le variazioni delle caratteristiche dell'olio di oliva vergine extra;usato come copertura di conserve alimentari, sono state esaminate in funcione dell'invecchiamento e delle condizione di confezioamento in un impiato industriale. Anche nelle piú blande condizioni di confezionamento (colmatura a mano con olio a temperatura ambiente) i limiti prescritti per l'olio di oliva vergine extra dal Regolamento CEE nº 2568/91 (cosi come da ultimo modificato dal Regolamento Ce nº 656/95) non sono più rispettati, nel caso piú favorevole, entro i 6 mesi ma più frequentemente entro 1 mese. Nel caso di un confezionamiento con impianto a regime la dequalificazione dell'olio d'oliva vergine extra avvienne ancor prima,per tempi di invecchiamento compresi fra 0 e 3 mesi, mentre per i prodotti confezionati dopo una fermata dell'impianto di 2 ore, in tuttii casi, l'olio di copertura e risultato fuori norm già all'uscita dal pastorizzatore cioè con invecchiamento 0.
Authors Guinda A.; Albi T.; De la Osa C.
Title Método rápido para la determinación de escualeno en aceites vegetales
Journal Grasas y Aceites, 46, 276-278
Abstract Se describe un método analítico, sencillo y rápido, para la cuantificación de escualeno en aceites comestibles. El método consiste en realizar primero una metilación alcalina en frío de la muestra grasa disuelta en hexano y, posterior análisis de la disolución de hexano por cromatografía gaseosa usando patrón interno. Se presentan una recta de calibrado con patrones cromatográficos puros, así como, los coeficientes de variación de muestras de aceites con alto, medio y bajo contenido en escualeno.
Authors Aparicio López R; Morales MT
Title Sensory Wheels: a Statistical Technique for Comparing QDA Panels. Application to Virgin Olive
Journal Journal of the Science of Food and Agriculture, 67, 247-257
Keywords chemometrics; olive oil; sensory analysis; sensory wheel;
Abstract The classic sensory wheel is used and modified to improve the objectivity and predictability of its conclusions concerning the best clusters of attributes. The full procedure was applied to 45 virgin olive oil samples representative of the most important producer countries and the main varieties marketed. The samples were evaluated by four different panels-Spanish; Italian, Dutch and British-these being representatives of traditional and potential consumers of this foodstuff. Altogether each sample was initially characterized by 86 sensory attributes. The relationships between sensory attributes are interpreted during the refinement process. Directions which promise to improve the EC standard on the sensory quality of olive oil are also given.
Authors Grob K; Bronz M; Biedermann M; Grolimund B; Boderius U; Neukom HP; Brunner M; Etter R; Giuffrè AM; Mariani C
Title Adulterated olive oils from the Swiss market 1993-1995
Journal Rivista Italiana delle Sostanze Grasse, 72, 525-528
Keywords olive; market; Adulteration;
Abstract Between 1993 and June 1995; 771 samples of olive oil from the Swiss market were analyzed for the detection of admixed other oils or of raffinates to oils sold as virgin. 236 (31%) of them were rejected. 52 oils sold as virgin contained excessive concentrations of stigmastadiene; for 184 samples, admixture of other oils was detected. This of rejected samples of olive oil is high, particularly when taking into account that many types of adulteration or unacceptable practices still remained undetected. Amounts of admixed oils were mostly small, showing the effect of improved control within the trade. On the other hand, the sophisticated pretreatment of many of the admixed oils indicates the strong interest in adulteration and the involvement of professionals experienced in oil technology and analytical chemistry. A large proportion of the adulterations was not detectable by the official methods. As frauds are rapidly adjusted to the analytical control, the latter needs constant improvement; restrictions in the application of innovative methods should be eliminated.
Authors Overton SV; Manura JJ
Title Analysis of Volatile Organics in Cooking Oils by Thermal Desorption-Gas Chromatography-Mass Spectrometry
Journal Journal of Agricultural and Food Chemistry, 43, 1314-1320
Keywords dynamic headspace; Flavor/aromas; olive oil; thermal desorptions;
Abstract Volatile organic compounds (VOCs) were collected from samples of 14 commercial olive oils and cooking oils using a purge and trap technique (P&T) and analyzed by thermal desorption-gas-chromatography-mass spectrometry (TD-GC-MS) to identify; compare, and quantify the volatile organics present. The P&T or dynamic headspace technique permits the analysis of wider range of both volatile and semivolatile organic compounds and is more sensitive by a factor of a least 100 as compared to the static headspace technique. No solvent extraction is required, which eliminates the exposure of laboratory personnel to these compounds and also eliminates the disposal of these solvents. This analytical method can be utilized for the quality control of these oils during production, can be used to detect adulteration or contamination of the pure product, and may provide for a 'fingerprint' chromatographic pattern for the comparison of oils or determination of origin.
Authors Jiménez de Blas O; Del Valle González A
Title Gas Chromatographic Differentiation of Virgin, Refined, and Solvent-Extracted Olive Oils
Journal Journal of the Association of Official Analytical Chemistry, 79, 707-710
Keywords gas chromatographic differentiation; Virgin olive oil; refined olive oil; solvent-extracted olive oil; trans isomers; sample; fatty acids;
Abstract An analytical method based on gas chromatography using a capillary column was used to determined fatty acids in olive oils. The method was applied to 50 samples of virgin olive oil; 50 of refined olive oil, and 30 of solvent-extracted olive oil. Results were compared, with special emphasis on peaks of minor fatty acids to distinguish virgin, refined, and solvent-extracted oils. Some peaks are probably due to trans isomers of the fatty acids. Statistically significant differences were observed among the 3 types of olive oil.
Authors Angerosa F; Lanza B; Marsilio V
Title Biogenesis of 'fusty' defect in virgin olive oils
Journal Grasas y Aceites, 47, 142-150
Keywords fusty defect; microorganism; Virgin olive oil; volatile compounds;
Abstract The biogenesis of 'fusty' defect was studied by chemical and microbial analyses on olives stored in piles for different times and their resulting oils. The fusty defect was perceived by tasters after four days of storage. The quali-quantitative composition of oil volatile fraction was a very suitable way to emphasize metabolites produced by microorganisms involved during the fruit storage. Some volatile compounds; such as 2- and 3- methyl butan-1-al, their corresponding alcohols and propionic acid, 2-methyl propionic acid and 3-methyl butanoic acid, were produced. At the same time, it was observed a dramatic development of Clostridium sp. and, in a lower proportion, of Pseudomonas sp. Furthermore, during the storage the evident softening of fruits has to be attributed to microorganisms in rapid growth belonging to Enterobacter sp. and moulds, that have in its enzymatic store pectinolytic enzymes.
Authors Gandul Rojas B; Mínguez-Mosquera MI
Title Chlorophyll and Carotenoid Composition in Virgin Olive Oils from Various Spanish Olive Varieties
Journal Journal of the Science of Food and Agriculture, 72, 31-39
Keywords carotenoid; chlorophyll; chlorophyllase; olive oil; pheophorbide; pheophytin; provitamin A;
Abstract A study of chlorophyll and carotenoid composition of nine single variety virgin olive oils from the main Spanish producing regions has shown differences depending on variety and ripening degree of the fruits. Pheophytin a was the major pigment in all the oils studied (44-58% total pigments) followed by lutein (18-38%) and b-carotene (6-17%). The chlorophyll pigments group also included pheophytin b and in some cases chlorophylls a and b. The carotenoid fraction also included the xanthophylls neoxanthin; violaxanthin, leuteoxanthin, antheraxanthin, mutatoxanthin and b-cryptoxanthin. The mean provitamin A activity of the oils was 260 mg Kg-1 expressed as retinol equivalent cis-a-Carotene (tentative). mono -and di-esterified xanthophylls and pheophorbide a were pigments exclusive to Arbequina variety, a fact that could be used as a chemo-taxonomic differentiator of the oils of this variety. The ratio between the chlorophyll fraction and the carotenoid fraction was maintained in most cases around 1, demonstrating that the green and yellow fractions were in balance, notwithstanding their greater or lesser total pigment content. The considerable range in the lutein /b-carotene ratio (between 1.3 and 5.1 depending on variety) makes this ratio a differentiator of single -variety oils. Despite the different sources of the oils, some general trends have been shown which suggest what chlorophyll and carotenoid pigments should be expected in an olive oil so as to include it within the denomination ' virgin '.
Authors García JM; Seller S; Pérez Camino MC
Title Influence of Fruit Ripening on Olive Oil Quality
Journal Journal of Agricultural and Food Chemistry, 44, 3516-3520
Keywords analytical determinations; Maturity; oil quality; Olea europaea; postharvest;
Abstract Olives (Olea europaea cv. Arbequina; Blanqueta, Lechin, Villalonga, and Verdial).used for oil production were harvested and distributed in four successive stages of ripening according to their skin color (green, spotted, purple, and black).The firmness of the fruits and the quality of the oils extracted from these fruits were analyzed. The resistance to postharvest handing measured by fruit firmness decreased during fruit ripening. The total oil content, the total oil extracted, and the a-tocopherol content did not change appreciably during this process. In general, the parameters which measure the oxidation of the oils extracted (K230, K270, and stability to oxidation) indicated a progressive deterioration of oil quality as fruit ripening progressed. Moreover, in this process bitterness indices decreased in the oils. The stage of ripening mainly affected the sensory quality of the oils obtained from the Verdial and Blanqueta varieties, which clearly decreased during fruit ripening.
Authors Morales MT; Aparicio López R; Calvente JJ
Title Influence of Olive Ripeness on the Concentration of Green Aroma Compounds in Virgin Olive Oil
Journal Flavour and Fragrance Journal, 11, 171-178
Keywords concentration; green sensory note; Olea europaea L; ripeness; statistics; Virgin olive oil; volatiles;
Abstract Changes have been demonstrated in the concentration of those volatile compounds responsible for green sensory notes in virgin olive oils obtained from four different varieties at three stages of ripeness. The information corresponding to each volatile compound for each stage of ripeness; after fuzzy filtering of the quantitative data, has been established and the relationship between volatile compounds and green sensory attributes has also been demonstrated by means of principal components analysis, correlation and stepwise linear regression analysis.
Authors Bonazzi M
Title Euro-Mediterranean Policies and Olive Oil: Competition or Job Sharing?
Journal The IPTS Report, 8, 16-22
Abstract Olive oil is nearly totally produced and consumed in the Mediterranean region; three quarters in the EU. However, demand of olive oil is expanding worldwide, especially in wealthy countries because of its healthy image. Driven by changes in world trade policies and technology,’ third' Mediterranean countries have a new opportunity for growth, reducing both poverty and migration, but they could become competitors of the EU producer countries. This is a case of possible contradictions between the international trade philosophies of a globalised open market and the Euro-Mediterranean space of cooperation. Olive oil could become a key--activity for the market--based cohesion objectives outlined in the context of the Euro-Mediterranean space of cooperation. The EU and 'third' Mediterranean countries should work together to optimize world market increase, employment rise and environmental preservation. This outlines the necessity of a concerted multilateral decision process between the EU and 'third' Mediterranean countries to define the playing fields of competition and complementarity between their different production patterns. Otherwise the existing gaps could be exacerbated. The role of technology has to be emphasized as pivotal for these purposes: it needs to address job-sharing and environmental objectives, examining the option of product and market differentiation without excluding strategies for the controlled mobility and training of the labour force throughout the whole Mediterranean region.This should enable the expected Euro--Mediterranean policy of co-development to optimize the potentialities for sharing growth and jobs all around the basin, targeting both market and technological prospects towards objectives of social justice and equity.
Authors Cañizares MP; Tena MT; Luque de Castro MD
Title On line coupling of a liquid-liquid extraction flow-reversal system to a spectrophotometric flow-through sensor for the determination of polyphenols in olive oil
Journal Analytica Chimica Acta, 323, 55-62
Keywords extraction; flow system; olive oil; polyphenols; Sensors; spectrophotometry;
Abstract The coupling of a liquid-liquid extraction approach based on flow-reversal to a flow-through sensor is proposed. The basis of the sensor is the use of Folin-Ciocalteau reagent immobilized on an anionic exchange resin packed in a flow cell located in a spectrophotometer; where the reaction product (molybdenum blue) is formed, retained and detected on the resin surface, thus integrating the reaction, retention and detection. The regeneration of the sensor is accomplished by passing an acidic Ce(IV) solution through it. This coupled system allows the extracted analyses (polyphenols) to be monitored continuously, and it was used to develop a method for the determination of polyphenols in oil. The proposed method features two linear response ranges, from 15 to 30 and from 30 to 90 mg ml-1,expresed as caffeic acid, with a relative standard deviation <3.1%. The 3s detection limit was 10 mg ml-1 caffeic acid. It was applied to the determination of polyphenols in olive oil samples with results in excellent agreement with those provided by a conventional method.
Authors Cert Ventulá A; Alba Mendoza J; León Camacho M; Moreda W; Pérez Camino MC
Title Effects of Talc Addition and Operating Mode on the Quality and Oxidative Stability of Virgin Olive Oils Obtained by Centrifugation
Journal Journal of Agricultural and Food Chemistry, 44, 3930-3934
Keywords stability; Virgin olive oil; talc addition; centrifugation mode; quality;
Abstract Continuous centrifugation a widely used procedure for extraction of virgin olive oil; involves crushing olives, mixing the olive paste, and centrifugation with or without water addition ('three phase' or 'two phase' modes respectively). Virgin olive oils were obtained following both procedures, with and without talc addition. Acidity value, peroxide index, UV absorption at 270 and 232 nm, glyceridic polar compounds, oxidized triglycerides, diglycerides, iron, copper, tocopherols, phenolic compounds, and oxidative stability were determined and the results statistically analyzed. The talc addition gave rise to a small increase in the oil stability and a slight decrease in oxidized triglyceride levels. The oils obtained by the ' two phase' mode showed a greater concentration of phenolic compounds than the homologous oils obtained by the 'three phase' mode. Oils processed by the 'three phase' mode showed a significant correlation between their stability and their phenolic concentration.
Authors Jiménez de Blas O; Del Valle González A
Title Determination of Sterols by Capillary Column Gas Chromatography Differentiation Among Different Types of Olive Oil: Virgin, Refined, and Solvent-Extracted
Journal Journal of the American Oil Chemists Society, 73, 1685-1689
Keywords Differentiation of oil types; olive oil; refined; solvent-extracted; sterol; virgin;
Abstract Compositional analysis of the sterol fraction of olive oil can be used to assess the degree of purity of the oil and the absence of admixture with other plant oils. This determination also permits characterization of the type of olive oil in question: virgin; refined, or solvent-extracted. In the present work, 130 samples of olive were analyzed, the sterol fractions were separated from the unsaponifiable fraction by silica gel plate chromatography, and later they were analyzed as the trimethylsilyl ether derivatives by capillary column gas chromatography. From the results obtained, it was concluded that this methodology is able to differentiate among virgin, refined, and solvent-extracted olive oils. Stigmasterol, clerosterol, D5-avenaterol, D7-stigmasterol, and D7 -avenasterol permit the differentiation of the three types of oil from one another. Campesterol, D5, 23-stigmastadienol, b-sitosterol, and D5,24-stigmastadienol permit the differentiation of only two oils from each other but confirm the conclusions obtained for other sterols. Correlations between the different sterols of virgin, refined, and solvent-extracted olive oil also have been obtained.
Authors Baldioli M; Servili M; Perretti G; Montedoro GF
Title Antioxidant Activity of Tocopherols and Phenolic Compounds of Virgin Olive Oil
Journal Journal of the American Oil Chemists Society, 73, 1590-1593
Keywords antioxidant; oxidation; phenols; Virgin olive oil; α-tocopherols;
Abstract The antioxidant effects of hydrophilic phenols and tocopherols on the oxidative stability in virgin olive oils and in purified olive oil have been evaluated. Total hydrophilic phenols and the oleosidic forms of 3;4-dihydroxyphenolethanol (3,4-DHPEA) were correlated (r = 0.97) with the oxidative stability of virgin olive oil. On the contrary, tocopherols showed low correlation (r = 0.05). Purified olive oil with the dialdehydic form of elenolic acid linked to 3,4-DHPEA, an isomer of oleuropeine aglycon, and 3,4-DHPEA had good oxidative stability. A synergistic effect was observed in the mixture of 3,4-DHPEA and its oleosidic forms with a-tocopherol in purified olive oil by the Rancimat method at 120ºC.
Authors Angerosa F; Giovacchino L
Title Natural antioxidants of virgin olive oil obtained by two and tri-phase centrifugal decanters
Journal Grasas y Aceites, 47, 247-254
Keywords Autoxidation (stability); natural antioxidant; tri phase centrifugal decanter; two phase centrifugal decanter; virgin olive oil;
Abstract The new dual-phase decanter does not require any addition of water to process olive paste and produces very limitated quantities of vegetable water. Consequently the elimination of big waste water problem makes particulary interesting this technological innovation. Therefore; in order to evaluate, in comparison with the traditional decanter, its effectiveness in relation to the quali-quantitative composition of natural antioxidants, tocopherols and phenolic compounds were determined on samples of virgin olive oils obtained by centrifugal decanters at two and three phases. Particularly, phenolic substances were analyzed by colorimetric, HPLC and HRGC methods. The results obtained proved that oils extracted by dualphase decanter had higher concentrations of both tocopherols and phenols, especially o-diphenols, and showed higher stability to oxidation. The resistance to oxidation appeared better correlated with the content of simple and linked o-diphenols and of aglycon of decarbomethoxy ligstroside.
Authors Angerosa F; D'Alessandro N; Corana F; Mellerio G
Title Characterization of phenolic and secoiridoid aglycons present in virgin olive oil by gas chromatography-chemical ionization mass spectrometry
Journal Journal of Chromatography A, 736, 195-203
Keywords aglycons; food analysis; glycosides; ligstroside; oleuropeins; olive oil; Phenolic compounds; secoiridoid; tyrosol; hydroxytyrosol;
Abstract Olive oil phenolic and secoiridoid compound derivatives were detected by mass spectrometry. Chemical ionization (CI) allowed us to obtain parent ions; that were not detectable in the electron impact mode.CI experiments were performed using either CH4 or NH3 as the reactant gas. Unlike CH4-CL which fails to give molecular mass information. NH3-CI provided, in all the cases explored, an adduct ion [M+18] that was sufficiently stable to be detected and recorded. Information about molecular masses was very useful for the complete characterization of aglycons from glycosides occurring in virgin olive oils Aglycons of ligstroside, of decarbomethoxyoleuropein and of oleuropein were detected. Each aglycon, because of several tautomeric equilibra involving the ring opening of secoiridoid, showed up as compounds with four main structures after derivatization with bis (trimethylsilyl) trifluoracetamide.
Authors Aparicio López R; Morales MT; Alonso MV
Title Relationship Between Volatile Compounds and Sensory Attributes of Olive Oils by the Sensory
Journal Journal of the American Oil Chemists Society, 73, 1253-1264
Keywords sensory attributes; statistical sensory wheel; Virgin olive oil; volatiles;
Abstract Sixty-five volatile compounds and 103 sensory attributes were evaluated in 32 virgin olive oil samples from three different Mediterranean countries. Volatile compounds were analyzed with a dynamic headspace gas-chromatographic technique by using a thermal desorption cold-trap injector. The sensory analysis was conducted by six panels composed of assessors from the United Kingdom; Spain, the Netherlands, Greece and Italy. Principal-components analysis sensory attributes was used to construct a statistical sensory wheel that represents the whole virgin olive oil flavor matrix. This wheel is composed of seven sectors that show the basic perceptions produced by the oil: green, bitter-pungent, undesirable, ripe olives, ripe fruit, fruity and sweet. The boundaries of each sector were calculated from the circular standard deviation of its sensory attributes. The relationship between sensory and instrumental analysis was determined by projecting volatiles onto the sensory wheel. Correlations of each volatile with the first two components of the principal-components analysis were taken as its coordinates (x,y) in the sensory wheel. Volatiles took up the most appropriate place within the sector that corresponded with their perception, and often close to the sensory attributes that explained their sensory properties. A gas-chromatographic/sniffing method was applied to virgin olive oil samples to assess the aroma notes that corresponded to olive oil volatile compounds and to verify relationships found by the sensory wheel procedure. Most (89%) of the volatiles were well classified. Use of the statistical sensory wheel as an appropriate method to relate volatile sensory data was clearly demonstrated.
Authors Aparicio López R; Calvente JJ; Morales MT
Title Sensory Authentication of European Extra-Virgin Olive Oil Varieties by Mathematical Procedures
Journal Journal of the Science of Food and Agriculture, 72, 435-447
Keywords chemometrics; flavour; fuzzy logic; olive oil; sensory profiling;
Abstract Multidimensional scaling and a fuzzy filter qualifier were used together for authenticating and characterizing four olive oil varieties-Picual and Arbequina (Spain); Coratina (Italy) and Koroneiki (Greece)- representative of the most important producer countries. Twenty four samples were evaluated by five panels of different nationalities-British, Greek, Italian and Spanish- these being representatives of traditional and potential consumers of virgin olive oil. Each sample was initially characterized by 74 sensory attributes. The paper analyses the most outstanding attributes and their evaluation intensities that characterize the varieties and gives the sensory profiling of each variety. Green attributes characterize Koroneiki variety, Arbequina variety is characterized by sweet-fruity sensory attributes, the bitter-pungent sensory attributes can identify Coratina while a strong fruity odour explains the sensory characteristics of Picual variety.
Authors Angerosa F; Di Giacinto L; Vito R; Cumitini S
Title Sensory Evaluation of Virgin Olive Oils by Artificial Neural Network Processing of Dynamic Head-Space Gas Chromatographic Data
Journal Journal of the Science of Food and Agriculture, 72, 323-328
Keywords head-space analysis; neural networks; olive oil; panel test;
Abstract A different approach to the traditional sensory method was used for the sensory quality evaluation of virgin olive oils. Two hundred and four oil samples differing in their quality; and extracted from olives of various varieties, ripeness, sanitary state and geographical origin, were submitted to sensory evaluation by a panel test and dynamic head-space analysis for the quantification of volatile fractions. An artificial neural network (ANN), using the back-propagation algorithm, was applied to the head-space results (input) with the aim of predicting panel test scores (output).It was found that the ANN was able to generalize well and to assign the sensory evaluations with a good degree of accuracy. The high proportion of correct answers (96%) suggested that sensory evaluation from the panel test could be successfully replaced by the dynamic head-space analysis-ANN coupled approach.
Authors Parras Rosa M
Title La demanda de aceites de oliva en el mundo
Journal Olivæ, 63, 24-33
Abstract En este artículo analizamos la situación actual y la evolución de la demanda de los aceites de oliva en el mundo. haciendo una especial referencia a los países de la Unión Europea. Para ello; partimos de las cifras absolutas y en términos per cápita del consumo de aceites de oliva por países. El artículo lo hemos estructurado en tres apartados, además del que destinamos a la introducción. En el primero de los epígrafes, estudiamos la situación actual de la demanda de aceites de oliva en el contexto de la demanda total de aceites vegetales comestibles y su evolución en los últimos veinticinco años, apuntando las causas que explican la dirección de la evolución. En el segundo apartado, repetimos el análisis descrito pero centrándonos solamente en la Unión Europea. Finalmente, en el último epígrafe, exponemos las conclusiones más relevantes extraídas del trabajo.
Authors Vlahov G; Angelo CS
Title The Structure of Triglycerides of Monovarietal Olive Oils: a 13C-NMR Comparative Study
Journal Fett-Lipid, 98, 203-205
Keywords 13C-NMR; olive; triglycerides;
Abstract The stereospecific distribution of major fatty acids between the 1;3- and 2-positions of glycerol in oil samples obtained from the same olive cultivar Leccino, grown in different Italian regions, Was studied by 13C-NMR- spectroscopy. By this method, the satured acids were found to be confined to 1,3-positions. Oleic and linoleic acids had common patterns of positional specificities, mostly in 2-position being that of the diunsaturated acid. The results obtained from the present study confirm that 13C-NMR represents a suitable method to perform the stereospecific analysis of olive sn-triglycerides. This paper reports on preliminary results of a research project aimed at defining a chemical basis for a varietal and geographical classification of olive oils.
Authors Biedermann M; Grob K; Mariani C; Schmidt JP
Title Detection of desterolized sunflower oil in olive through isomerized D 7-sterols
Journal Zeitschrift für Lebensmittel Untersuchung und-Forschung, 202, 199-204
Keywords Desterolization; sunflower oil; Isomerized Δ7-Sterols; Δ8 (14)- Sterols; olive oil;
Abstract Adulteration of expensive edible oils; such as olive oil, often involves desterolized oils in order to render the adulteration undetectable. Sunflower oil contains characteristic D7-sterols, which are readily removed upon strong bleaching. It is shown that these D7-sterols do not primarily dehydrate (as do D5-sterols), but isomerized to D8(14)- and D14-sterols. These compounds can be analyzed by LC on silica gel or GC on capillary columns with stationary phases of intermediate to high polarity.
Authors Wesley IJ; Pacheco F; McGill AEJ
Title Identification of Adulterants in Olive Oils
Journal Journal of the American Oil Chemists Society, 73, 515-518
Keywords discriminant analysis; Near-Infrared Spectroscopy; olive oil; principal component analysis;
Abstract The application of discriminant analysis for identifying and quantifying adulterant in extra virgin olive oils is presented. Three adulterants were used (sunflower oil; rapesed oil, and soybean oil) and were presented in the range 5-95%. near-infrared spectroscopy and principal components analysis were used to develop a discriminant analysis equation that could identify correctly the type of seed oil present in extra virgin olive oil in 90% of cases. Partial least squares analysis was used to develop a calibration equation that could predict the level adulteration. Cross validation suggested that it was possible to measure the level of adulteration to an accuracy of +/-0.9%. External validation of the derived calibration equation gave a standard error of performance of +/- 2.77%.
Authors Mincione B; Poiana M; Giuffrè AM; Modafferi V; Giuffrè F
Title Ricerche sugli oli di oliva monovarietali. Nota II. Caratterizzazione del´olio di Peranzana
Journal Rivista Italiana delle Sostanze Grasse, 73, 245-257
Keywords Monovariety olive oils;
Abstract Research was carried out on the monovariety olive oils from Southern Italy, specifically from the Peranzana Cultivar. Various aspects were considered from the evaluation of the raw material (cv Peranzana and cv Rotondella) to a detailed analytical study of the produced oil. On average the yield was 18%. the oil having excellent quality characteristics and biological stability. The triglyceride structure was as follows: LnLnLn. LLnLn. LLLn, LLL, PoLL, OLLn, OLL. OOLn, PLL, OOL, POL, SLL, OOO. POO, PPO, SOO, with the OOL triglyceride present in the greatest amount. The acidic profile was the following: palmitic, margaric, stearic. arachic, behenic, and lignoceric, amongst the saturated acids, and palmitoleic, eptadecenoic, oleic, linoleic, linolenic, eicosenoic, amongst the unsaturated acids. With an average of 72%, the oleic acid was the main constituent.
The sterols were identified in the following elution order cholesterol. campesterol, campestanol, stigmasterol, Δ7-campesterol, clerosterol, β-sitosterol, Δ5-avenasterol, Δ5'24-stigmastadienol, Δ7-stigmastenol, Δ5-avenasterol, being β-sitosterol the exceeding one (83.42% maximum value). The presence of eritrodiol+uvaol and total sterols reached 4% and 1582 ppm respectively. The phenolic fraction consisted of: tirosol, vanillic, caffeic, siringic, p-cumaric, sinapic, o-cumaric and cinnamic acids, tirosol having the highest value with a maximum of 19759 ppb. The chlorophyll and carotene content and the chromatic evaluation all contributed to a better characterization of the Peranzana oil. The presence of phosphorganic pesticide residue was as follows: metidathion, malathion, fenthion, parathion-metile. The values, however, were far below the fixed minimum limits.
Authors Angerosa F; Di Giacinto L; Serraiocco A
Title Influenza della variabile ' da lambiente ' sulla composizione degli oli virgine di oliva
Journal Rivista Italiana delle Sostanze Grasse, 73, 461-467
Abstract Oil samples obtained from olives of Frantoio variety harvested in Spoleto (PG); Vetralia (VT) and Canneto (RI),and from fruits of 177 cultivar harvested in Perugia, Atessa (CH) and Francavilla Fontana (BR) were submitted to sensory and instrumental analyses. 149 variables were analyzed by Principal Component Analysis (PCA) in order to identify the analytical parameters that showed the better discrimination of samples in relation to the geographical areas of olive cultivation. These areas were also characterized surveying pedoclimatic data. The Partial Least Squares regression (PLS2) applied to the instrumental vs. pedoclimatic data matrices, evidenced good correlations. Sterols, squalene, oleic acid and long chain esters, some triacylglycerols, oleic acid/linoleic acid and phytol were connected to the autumn temperatures, the relative humidity of summer months and the rainfall of the whole year. Furthermore phosphorus and nitrogen contents of the soils of 177 cultivation were correlated with the same analytical parameters.
Authors De Leonardis A; De Felice M; Macciola V
Title Studio sulla composizione acidica degli oli vergini di oliva del Basso Molise
Journal Rivista Italiana delle Sostanze Grasse, 73, 321-325
Keywords extra virgin olive oil; fatty acid;
Abstract This article reports the results of an analytical study effected in the period 1993-96 on virgin oils from the lower. Molise region. In particular; we studied the fatty acid composition of industrially - produced oils and others which were extracted in laboratory from eleven olive cultivars. With the exception of oils from Colletorto, which present a higher average percentage of palmitic acid (14.0) and lower oleic acid content (69.0%) we have found that the oils from Molise, are, generally, characterized by high oleic acid content. The analytical comparison between oils of several cultivar demonstrated that there exists a high level of variability. The oils from Coratina, Leccino and Rosciola di Rotello cultivars were characterized by high oleic acid content (> 77.6%) lower linoleic acid quantities (< 6%) and also by very high C 18: 1/C 18:2 values (> 14).
Authors Di Giovacchino L
Title Influencia de los sistemas de extracción en la calidad del aceite de oliva
Journal Olivæ, 63, 52-63
Keywords extraction system; olive oil quality;
Authors Vlahov G
Title Improved Quantitative 13C Nuclear Magnetic Resonance Criteria for Determination of Grades of Virgin Olive Oils. The Normal Ranges for Diglycerides in Olive Oil
Journal Journal of the American Oil Chemists Society, 73, 1201-1203
Keywords Glycerides; quantitative 13C NMR; Virgin olive oil;
Abstract A quantitative method was established to determine the presence and composition of mono-;di-. and triglycerides of olive oils of superior grade via 13C NMR. The total diglyceride content and the ratio of sn-1,2- and sn-1.3- diglycerides in extra virgin oils extracted from different olive cultivars were correlated with maturity. The correlation can be applied to identify the oils by variety. No monoglycerides were detected in the oils examined.
Authors Esti M; Cinquanta L; Carrone A; Trivisonno MC; La Notte E; Gambacorta G
Title Composti antiossidanti e parametri qualitativi di oli vergini di oliva prodotti in Molise
Journal Rivista Italiana delle Sostanze Grasse, 73, 147-150
Keywords Anti-oxidative compounds and quality parameters in virgin olive;
Abstract The investigation on qualitative and composition characteristics of virgin olive oil produced in Molise; continued in 1993 on single -variety samples chosen among the most widely-grown olive cultivars in that Region. Beyond organic acidity, peroxide and UV absorption, the analytical evaluation included also fatty acid composition, content of total polyphenols and a-tocopherol, HPLC of the phenolic fractions, as well as organoleptic test. The results obtained stress that, when the environmental conditions are favorable, the qualitative characteristics of the product are in accordance with those required for the extra virgin grading. The contents of phenolic substances and a -tocopherol were very close to the average values of Italian oils. Moreover, the content of the simple phenolic fraction showed a significant increase at 6 months storage. Organoleptic evaluation of the samples resulted in perceiving a light fruity flavour and mainly, an aromatic nuance of ripe fruits.
Authors Alba Mendoza J; Hidalgo Casado F; Ruiz Gómez MA; Martínez Román F; Moyano Pérez MJ; Cert Ventulá A; Pérez Camino MC; Ruiz Méndez MV
Title Características de los aceites de oliva de primera y segunda centrifugación
Journal Grasas y Aceites, 47, 163-181
Keywords Olive oil; Second centrifugation; 2nd centrifugation pomace; Elaboration;
Abstract Características de los aceites de oliva de primera y segunda centrifugación. En este trabajo se ha estudiado la viabilidad de la segunda centrifugación utilizada como; sistema para mejorar el agotamiento de los orujos producidos por el nuevo sistema de elaboración de aceite de oliva virgen por centrifugación en dos fases así como su influencia en las principales características analíticas de los productos y subproductos que intervienen en el proceso. Para ello se han analizado las muestras obtenidas en los ensayos comparativos de primera y segunda centrifugación en fresco y de primera segunda y tercera centrifugación de masas de aceitunas centrifugadas y almacenadas. Se ha realizado también un ensayo de decoloración de los aceites obtenidos con el fin de ver como afectan estos procesos a los distintos sistemas de refinación (física y química).Los resultados obtenidos ponen de manifiesto fundamentalmente,la necesidad de realizar la segunda centrifugación en fresco y a moderadas temperaturas para obtener aceites con parámetros de calidad y pureza dentro de los límites establecidos en la reglamentación para aceites de oliva virgen.
Authors Tubaro F; Micossi E; Ursini F
Title The Antioxidant Capacity of Complex Mixtures by Kinetic Analysis of Crocin Bleaching Inhibition
Journal Journal of the American Oil Chemists Society, 73, 173-179
Keywords analysis; carotenoid; competition; Data processing; kinetics; mixture; processing; water; antioxidant; crocin; diazo-compounds; Mail-lard reaction; olive oil; peroxyl radicals; rosemary;
Abstract The capacity a compound or of a mixture of compounds to quench peroxyl radicals was measured by analyzing the kinetics of the competition of a parallel reaction where peroxyl radicals bleach the carotenoid crocin. This kinetic approach; originally described for the analysis of antioxidants reacting with hydroxyl radicals in water, was no modified by both decreasing the polarity of the solvent, thus allowing the analysis of lipophilic compounds, and by substituting a source of peroxyl radicals for the hydroxyl radical generating system. Single compounds as well as complex mixtures were analyzed by kinetic data processing. Overall antioxidant capacity, relative to that of a-tocopherol or of its soluble analog Trolox C, was calculated. As examples of the use of this test, the antioxidant capacities of a crude rosemary extract, Maillard rection products, and virgin olive oils were measured.
Authors Imperato A
Title Isolamento delle cere negli oli di oliva mediante cromatografia su colonna: nota all'allegato IV del Regolamento CEE 2568/91
Journal Rivista Italiana delle Sostanze Grasse, 73, 265-266
Keywords waxes isolation; olive oil; column chromatography;
Abstract A method for the complete and repeatable recovery of olive oil waxes is proposed. The results are compared with those obtained by using the official method.
Authors Muñoz Vilches RM; Gómez Muñoz AC
Title Funciones de respuesta asimétrica: el caso de la demanda de aceite de oliva en España
Journal Olivæ, 60, 9-13
Keywords Aceite de oliva;
Authors Koprivnjak O; Conte LS
Title Caratteristiche della frazione idrocarburica e composizione degli acidi grassi degli oli d´oliva vergini provenienti dalla zona di Pola (Croazia)
Journal Rivista Italiana delle Sostanze Grasse, 73, 317-320
Keywords fatty acid; Virgin olive oil;
Abstract Recent market trends dealing with typical products involve the availability of analytical methods suitable for accurate characterization of the oil origin. Recently; some papers of Spanish researchers appeared in the literature dealing with the study of hydrocarbon fraction as an useful analytical tool for recognizing the cultivar. In the present paper, samples of oils produced in the Pula area (Croazia) from the cultivar Bianchera, Busa, and Carbonazza (autochthonous) and an introduced one (Leccino) were analyzed as regard the hydrocarbon fraction. The results evidenciated the presence of unsaturated hydrocarbons and different distribution of other congeners in the autochthonous cultivars and in the introduced one.
Authors Koutsaftakis A; Stefanoudaki E; Iconomoy D
Title Risultati ottenuti dall´estrazione del´olio d´oliva con pressa continua orizzontale a vite
Journal Rivista Italiana delle Sostanze Grasse, 73, 93-96
Keywords extraction; olive oil;
Abstract A of experiments have been carried out using a continuous screw press for the extraction of olive oil. Oil was collected in a receptacle which was divided in three sections in relation to exercised pressure. Loops of different diameters and housing cone orifices size were tested. Results showed that the minimum oil and moisture content of the husk can be achieved with a loop of 90 mm diameter and a housing cone with diameter of orifices 0.9 mm. The highest industrial yield was obtained with 30 minutes mixing time and at paste temperature 30 ºC. The qualitative characteristics acidity; peroxide value, absorption coefficients K232 and K270 of the olive oil from the different parts of the reception container showed no differences. However the amount of total phenols and the tolerance to rancidity was higher in section one.
Authors Losi G; Pallotta U
Title Sulla composizione degli oli di oliva italiani
Journal Rivista Italiana delle Sostanze Grasse, 43, 425-430
Abstract Some physical and chemical determinations have been performed on a series of samples of virgin olive oils drawn from the various italian oil-producing regions. On every sample the following determinations have been performed: refractive index; organic acidity, iodine , peroxide , spectrophotometric analysis in the ultraviolet and gaschromatographic analysis with polar and non polar capillary columns. The last technique allowed to confirm the data on the acidic composition of olive oils of our own country obtained by other Authors, and to note some fatty acids that are present in small quantities and that are signaled for the first time among the constituents of the Italian genuine olive oils.
Authors Mariani C; Venturini S
Title Sull´aumento delle cere durante la conservazione degli oli di oliva
Journal Rivista Italiana delle Sostanze Grasse, 73, 489-498
Keywords cere; olive oil; storage; waxes increasing;
Abstract Earlier experiments had shown that contents of waxes and esters associated with the alcoholic fraction and free sterols could increase in olive oil during storage [see C. Mariani et al.; Rivista Italiana delle Sostanze Grasse (1989) 66, 447]. To establish whether this increase was due to natural phenomena or external influences, various types of olive oil (virgin, extra virgin, including samples from Greek analytical laboratories) were aged after addition of different alcoholic compounds not present naturally. It was shown that, after a short time, products of esterification with the oil's free fatty acids were found in the samples studied. The process was confirmed in further tests in which, when fatty acids and the alcoholic components were mixed in a hydrocarbon matrix, ester neoformation was again observed. It is concluded that the esterification process occurring in olive oils is a natural phenomenon and not attributable to outside causes, the rate of esterification being influenced by the storage conditions.
Authors Esti M; Gambacorta G; Carrone A; Trivisonno MC
Title Caratteristiche qualitative e compositive di oli vergini di oliva prodotti in Molise
Journal Rivista Italiana delle Sostanze Grasse, 73, 101-106
Keywords virgin olive oil (characterization);
Abstract This study was carried out on virgin olive oils produced in Molise in 1992 and was aimed at a first assessment of the characteristics of the product in view of its future typing. We examined two groups of samples; one was made of olive oils obtained through pressing in oil mills located in several olive producing areas in Molise; the other was produced from single-variety olives through mechanical extraction in the laboratory. Beyond the chemical-physical qualitative parameters the acidic and sterolic composition and, for some samples, the triglycerides and aliphatic alcohols were determined. The wide variability observed for some qualitative parameters was probably due to seasonal trends and to the widespread practice of storing olives in the mills for some days. The acidic and sterolic compositions of the samples showed rather high values of oleic acid on average, and small differences in the content of b-sitosterol and D5- avenasterol.
Authors Guinda A; Lanzón A; Albi T
Title Differences in Hydrocarbons of Virgin Olive Obtained from Several Olive Varieties
Journal Journal of Agricultural and Food Chemistry, 44, 1723-1726
Keywords hydrocarbons; olive varieties; virgin olive oil;
Abstract An analytical method has been developed to study; as a whole, the hydrocarbon fraction-other than squalene-of virgin olive oils. This method was applied to the study of oils from representative olive varieties of Spanish olive groves: Arbequina, Cornicabra, Empeltre, Hojiblanca, and Picual. The composition profiles of some of the hydrocarbons of oils from the above mentioned varieties are shown in this paper. The ranges of concentration in milligram per kilogram of oil of these hydrocarbons are also shown. Significant differences in the content of some hydrocarbons of the five varieties analyzed were observed. These quantitative differences were used to distinguish between virgin olive oils from different olive varieties.
Authors Christopoulou E; Lazaraki M; Alexiou F; Synouri S; Frangisco E
Title Influence of certain factors on the composition of olive-pomace oils. Part II Sterols, triterpenic dialcohols and aliphatic alcohols
Journal Rivista Italiana delle Sostanze Grasse, 73, 201-211
Abstract In the present work the composition of sterols; triterpenic dialcohols and aliphatic alcohols in the different parts of the olive-tree fruit is examined, in order to interpreted differences in the composition of virgin olive oil and olive- pomace oil.Samples of two varieties of olive-fruit were studied (Koroneiki and Kolovi) and significant differences were noted in the composition of the different parts of the olive-fruit. In particular, the olive stone-oil has a high concentration of campesterol, b-sitosterol, sitostanol and total sterols and low concentration of D5-avenasterol and apparent b-sitosterol. On the other hand, a very high content of erythrodiol, uvaol and aliphatic alcohols is accumulated in the flesh and skin, the concentration of erythrodiol being particulary high in the skin. Results demonstrate that the aforementioned differences, which depend significantly on the olive variety, are also reflected in the composition of virgin olive oil and olive- pomace oil. Consequently, olives of small size may produce pomace oil with a low concentration of apparent b-sitosterol and a high concentration of campesterol. Verification of the above is the fact that the type of oil mills affects the composition of olive-pomace oil. The strong correlation coefficients between most of the sterols present in all the parts of olive fruit are also noteworthy and reveal a part of the profile of the olive-fruit.
Authors Ranalli A; Serraiocco A
Title Evaluation of characteristics of olive oil produced by innovative or traditional processing
Journal Rivista Italiana delle Sostanze Grasse, 73, 303-315
Keywords extraction system; hydrocarbons; olive oil; sterols; volatile;
Abstract The qualitative level of oils produced by the recent two-phase continuous systems was two-phase continuous systems was evaluated by comparing their characteristics with those of pressing oils. Homogeneous lots of olives (Grossa di Cassano; Caroleo and Coratina varieties) of good quality were industrially processed. The extraction of oil from drupes was carried out in a rational and rigorous manner in order to obtain a product without defects (which could distort the results of comparisons). Numerous analyses were performed on resulting oils in order to almost all the parameters and indices related to their quality. The oils produce were also pyrolised (at the Curie point) and the data relating to the pyrolysis-mass spectra (pyrograms or framentgrams) were processed by applying both, classic and neural statical multivariate analysis methods.
Well, the oils extracted by pressing system, in the operating conditions adopted, exhibited better qualitative characteristics, and particular were characterized by higher content of total minor polar components (MPC), hydrolysable phenol and tocopherols; and furthermore by higher values of oxidate stability, higher values of global quality indices and higher sensory scores; but by lower values of trans2-hexenal content trans-2hexenal/hexenal ratio and trans-2 hexenal/total aroma ratio. Traditional system led also to obtain higher processing quantitative outputs. The better general qualitative (and quantitative) results, that the classic system allowed to obtain are probably to be ascribed to the crusher type adopted (mill-stone) by such technological cycle (rather than to the modality of separation of liquid phases from that solid.) However the integral continuous system led to obtain oils of elevate quality itself, more aromatic, and for some aspects comparable with those from traditional procedure. So that we believe that the new decanters (with which was possible to avoid or considerable reduce the dilution water of pastes), will be the extractors adopted at a near future, all the more that they may combined with millstone themselves, and because the oil produced by them are usually without defects.
Authors Bonazzi M
Title L'huile d'olive en progression, les huiles mélangées passent à l'attaque
Journal The IPTS Report, 4, 20-24
Abstract L'huile d'olive assure la revenu based' environ deux millions de familles dans le sud de l'U.E. et de prés de trois millions de familles dans les pays mediterranéens. Il s'agit en outre; d'une denrée fondamentale pour les habitudes alimentaires et culturelles de ces pays. Bon nombre d'entre eux investissent lourdement dans le secteur de l'huile d'olive, afin de tirer le meilleur parti des évolutions technologiques, de la restructuration de l'emploi et de l'expansion des marchés d'exportation. Dans ce contexte, l'arrivée d'imitations économiques basées sur des mélanges d´huiles pourrait menacer á la fois l'identité culturelle et l'économie de nombreuses régions d'Éspagne, d'Italie, de Grèce, du Portugal et du Maghreb, et entrainer une augmentation du chômage de 15%. Cette situation exige l'application de politiques extrêmement prudentes, les conflits d'intérêts actuels menaçant de contrecarrer les opportunités de développement de la région méditerranéenne offertes par la croissance du secteur de l'huile d'olive.
Authors Di Giovacchino L; Angerosa F; Di Giacinto L
Title Effect of Mixing Leaves with Olives on Organoleptic Quality of Oil Obtained Centrifugation
Journal Journal of the American Oil Chemists Society, 73, 371-374
Keywords Metal crusher; mixed olives-leaves; olive oil quality;
Abstract Variable quantities of leaves were added to ripe olives prior to extraction to determine their effect on the quality of the resulting olive oil. The addition of 1--3% w/w leaves improved the organoleptic quality. An increase in trans -2-hexenal aldehyde content occurred; giving the pleasant flavor of ' freshly cut grass '. This compound was produced by the enzymatic breakdown of 13-L-hydroperoxide of linolenic acid in leaf homogenates.
Authors Ranalli A; Angerosa F
Title Integral Centrifuges for Olive Oil Extraction. The Qualitative Characteristics of Products
Journal Journal of the American Oil Chemists Society, 73, 417-422
Keywords Integral centrifuges; olive oil extraction; qualitative characteristics of oil;
Abstract Oil extraction experiments with three olive varieties (Coratina; Nebbio and Grossa di Cassano) were carried out to compare the two-phase centrifugal decanter with conventional tree-phase equipment. The results showed that the two-phase centrifugal extractor renders better qualitative characteristics in the oils, which were comparable to pressed of filtered oils. The two-phase decanter product exhibited higher contents of polyphenols, orto-diphenols, hydroxytyrosol, tocopherols, trans-2-hexenal and total aromatic volatile substances. Furthermore, the oils received a higher sensorial score and were characterized by higher values of oxidative stability and campesterol/stigmasterol ratio; lower values of turbidity, alcohol index and chromatic indices; Lower content and aliphatic and triterpenic alcohols.
Authors Mousa MY; Gerasopoulos D
Title Effect of Altitude on Fruit and Oil Quality Characteristics of 'Mastoides' Olives
Journal Journal of the Science of Food and Agriculture, 71, 345-350
Keywords cv 'Mastoides'; fatty acids; olive oil quality; olive tree; Phenolic compounds;
Abstract Olive fruit of cv 'Mastoides' grown on two locations at altitudes of 100 and 800 m were harvested at three dates and used for determination of average weight; fruit oil and moisture contents and the following oil quality characteristics: titratable acidity, peroxide value, K232,270 coefficients, total phenol, tocopherol and chlorophyll content as well as fatty acid and phenol composition. Towards maturation, fruit moisture content decreased but oil content increased. Titratable acidity of oil of both altitudes was low, with higher the oil obtained from fruits from 100 m. Oil peroxide value was higher in the oil of fruits from 800 m at all harvest times and it showed an increase towards maturation in both locations. Total phenol content was higher in oil from 100 m elevation and showed a gradual decrease towards maturation at both altitudes. the ratio unsaturated saturated fatty acids was higher in oil of fruits from 800 m at the first two harvest dates but did not differ significantly at the third harvest. Only a - tocopherol was found in the oil from both elevations. Some phenolic compounds were detected in the first harvest appeared later. Elevation influenced not only the phenol content but also its composition.
Authors Gandul Rojas B; Mínguez-Mosquera MI
Title Chlorophyllase Activity in Olive Fruits and its Relationship with the Loss of Chlorophyll Pigments in the Fruits and Oils
Journal Journal of the Science of Food and Agriculture, 72, 291-294
Keywords chlorophyllase; olive; oil; chlorophyll; pheophytin; pheophorbide; enzyme; color;
Abstract Chlorophyllase activity in fruit and chlorophyll pigment content in both fruits and their corresponding oils were studied in ripe olives of Arbequina and Picual varieties. It was demonstrated that the process of extraction of the virgin oil; as well as propitiating the pheophytinisation of chlorophylls initially present in the fresh fruit, also leads to marked losses of the chlorophyllic pigments. These losses were more acute in the Picual variety than in the Arbequina variety. Given that the levels of chlorophyllase activity measured in the fruits of the Arbequina variety were 100 times greater than those in the Picual variety it is not possible to attribute the loss of chlorophyll pigments to activation of chlorophyllase during oil processing.
Authors Sacchi R; Patumi M; Fontanazza G; Barone P; Fiordiponti P; Mannina L; Rossi E; Segre AL
Title A High-Field 1H Nuclear Magnetic Resonance Study of the Minor Components in Virgin Olive Oils
Journal Journal of the American Oil Chemists Society, 73, 747-758
Keywords olive varieties; quality; Virgin olive oil;
Abstract High-field (600MHz) nuclear magnetic resonance (NMR) spectroscopy was applied to the direct analysis of virgin olive oil. Minor components were studied to assess oil quality and genuineness. Unsaturated and saturated aldehyde resonances; as well as those related to other volatile compounds, were identified in the low-field region of the spectrum by two-dimensional techniques. Unsaturated aldehydes can be related to the sensory quality of oils. Other unidentified peaks are due to volatile components, because they disappear after nitrogen fluxing. The statical analysis performed on the intensity of these peaks in several oil samples, obtained from different olive varieties, allows clustering and identification of oils arising from the same olive variety. Diacylglycerols, linolenic acid, other volatile components water, acetic acid, phenols, and sterol can be detected simultaneously, suggesting a useful application of high-field NMR n the authentication and quality assessment of virgin olive oil.
Authors Poiana M; Giuffrè AM; Giuffrè F; Modafferi V; Neri A; Mincione B; Taccone PL
Title Ricerche sugli oli di oliva monovarietali. Nota IV. Contributo alla caratterizzazione dell'olio estratto da olive della cv Nocellara messinese
Journal Rivista Italiana delle Sostanze Grasse, 74, 59-71
Keywords Monovariety olive oils;
Abstract In a series of researches about monovariety olive oils produced in the South of Italy, the oil extracted from Nocellara messinese cv olives harvested in a area of Reggio Calabria district was analyzed.
The analyses were performed during the olive ripening from October to January. On the drupe the following analyses were performed: maturity index, drupe weight and its dimension, oil content. On the olive pulp were determined the dry matter (34% in average), and the oil content (36% on dry matter). The oil extracted by a mini oil-mill was analyzed for the organic acidity, peroxide , induction time measured at Rancimat apparatus, total polyphenols, carotenes and chlorophyll. The spectrophotometric determinations were agreed with Community rules. Triglycerides were analyzed by HPLC and 22 chromatographic peaks, corresponding to 30 triacylglycerols, were separated. The most represented were: OOO (27-33%), OOL + PoOO (19-21%), POO + SOL (19-21%), POL + PPoO (10-12%), OLL (4-6%), PPO + PLS (3-4%), SOO (2-3%). An high content of linoleic acid was measured by GC (14-18%) compared to other olive oils. The concentration of oleic and linoleic acid could be a differentiation element from other olive cultivars. The sterolic composition was similar to other olive oils, but at the end of ripening the Δ7-stigmastenol content higher than 0.5% were quantified. The total content of sterols showed a decreas during the sampling but it was ever higher than 1300 ppm. Low levels of alkanols (20-75 ppm) and waxes (30-50 ppm) were measured. The following phenols were separed and identified by HPLC: hydroxytyrosol, tyrosol, vanillic acid, caffeic acid, siringic acid, p- and o-coumaric acid, ferulic acid, sinapic acid, oleuropein, cynnamic acid. Three not yet indentified compounds x1, x2 and x3 were present in great amount in the phenolic fraction.
Authors Aparicio López R; Morales MT; Alonso V
Title Authentification of European Virgin Olive Oils by Their Chemical Compounds Sensory Attributes and consumers Attitudes
Journal Journal of Agricultural and Food Chemistry, 45, 1076-1083
Keywords analysis; authenticity; consumers' attitudes; Flavor; Virgin olive oil;
Abstract Twenty-four samples of four European virgin olive oil varieties-Arbequina; Coratina, Koroneiki, and Picual cultivated in Greece, Italy, and Spain-have been analyzed from their chemical composition (either nonvolatile compounds (31)-fatty acids, sterols, alcohols, and methylsterols-Or volatile ones (659-aldehydes, alcohols, furans, hydrocarbons, acids, ketones, and esters), sensory attributes (103), and consumers' attitudes, the latter in terms of their overall acceptability and sensory comments from their acceptability trials. The paper describes and explains the most remarkable of these parameters characterizing the virgin olive oil varieties, which can be useful in virgin olive oil authentication. the agreement between the concentration of chemical compounds and sensory attributes is explained wherever possible.
Authors Paganuzzi V
Title Sulle attuali posibili sofisticazioni dell'olio di oliva
Journal Rivista Italiana delle Sostanze Grasse, 74, 49-58
Keywords Adulterations of olive oil;
Abstract Sono prese in considerazione le composizioni e le attuali quotazioni degli oli di oliva; dei principali oli vegetali commestibili e, fra questi, di quelli che, per il loro basso prezzo e per la difficoltà di evidenciarli se addzionati agli oli di oliva al di sotto di una certa percentuale, possono essere impiegati per sofisticare questi ultimi. Per ognuno dei potenziali adulteranti considerati viene volutato il livello di sofisticazione possibile, rimanendo entro i limiti prescritti dal Reg. CEE nº 2568/91 per l'olio di oliva per i parametri in esso attualmente contemplati. Si esaminano infine le indicazioni della più recente letterature che permetterebbero di ridurre il livello delle frodi prese in considerazione.
Authors Morales MT; Rios JJ; Aparicio López R
Title Changes in the Volatile Composition of Virgin Olive Oil during Oxidation: Flavors and Off-Flavors
Journal Journal of Agricultural and Food Chemistry, 45, 2666-2673
Keywords oxidation; volatiles; Flavor; off-flavor; Virgin olive oil;
Abstract A thermoxidation process has been applied to extra-virgin olive oil to develop new knowledge on the evolution of the volatile compounds responsible for virgin olive oil flavor during oxidative deterioration. The initial volatiles (a total of 60); many of them responsible for the pleasant sensory characteristics of the oil and produced mainly through biochemical pathways, disappeared in the first hours, and the formation of off-flavors, produced through oxidative pathways, gradually increased. The main volatile compounds possibly responsible for off-flavors (51) were identified, and their evolution during the oxidative process was studied. The fatty acids content was determined during the process. Unsaturated fatty acids were found to be the main precursors of the volatile compounds found in oxidized samples. The early measurement of nonanal (which was not detected at all, or only at trace levels, in extra-virgin olive oil samples) could be an appropriate method to detect the beginning of the oxidation. The ratio hexanal/nonanal was used to differentiate between oxidized and good-quality virgin olive oil samples. Sensory evaluation of the samples and peroxide value agreed on the evolution of the oxidation.
Authors Mordret F; Coustille JL; Lacoste F
Title Méthodes physico-chimiques d´analyse des huiles d´olive
Journal Oléagineux Corps gras Lipides, 4, 364-369
Keywords analysis; olive oil; quality control; regulation;
Abstract Olive oil in respect of its particularities is submitted to a full quality control program; mainly based on the application of physical-chemical analysis in order to precise its freshness, purity and the absence of contaminant. Most of the determinations, either classical (acidity, peroxide value) or more sophisticated (ECN42, triglycerides, sterenes) and specifications are precised in the Trade Standard of the International Olive Oil Council (IOOC) as well as the European Regulation. Some examples of analysis and results are produced; the possible application of new techniques for checking technological criteria (cold-press oil) or the origin of the oil (authentification) are also mentioned.
Authors Salas J; Pastor M; Castro J; Vega V
Title Influencia del riego sobre la composición y características organolépticas del aceite de oliva
Journal Grasas y Aceites, 48, 74-82
Keywords bitter taste; fatty acid; Irrigation; olive tree; quality; Virgin olive oil;
Abstract Se estudia la composición relativa en ácidos grasos; características organolépticas y parámetros de calidad de los aceites producidos en olivares de secano o regados con diferentes dosis de agua. La composición acídica fue alterada por el riego. El contenido en ácidos grasos monoinsaturados y poliinsaturados fue mayor en los aceites de secano, mientras que el contenido relativo en ácidos grasos saturados fue mayor en regadío Las relaciones insaturados/saturados y oleico/linoleico diferencian los aceites de riego y de secano. Existió una relación entre los valores de K225, El contenido en polifenoles y el grado de amargor, siendo los aceites de secano mucho más amargos que los de riego, discriminando estos tres parámetros los aceites de riego y los de secano. El grado de amargor disminuyó al aumentar la cantidad de agua aportada con el riego.
Authors Mucciarella MR; Marsilio V
Title Influenza del processo tecnologico di preparazione e della conservazione sulle caractteristiche chimico-fisiche dell'olio di oliva vergine extra usato come copertura di conserve vegetali in vasetti di vetro
Journal Rivista Italiana delle Sostanze Grasse, 74, 105-112
Keywords extra virgin olive oil;
Abstract The influence of the process treatments and of the ageing time on the extra virgin olive oil in some vegetables canned in glass vessel has been examined. The various phases of preparation and the storage conditions of the canned foods have been described. Analytical results have shown that the extra virgin olive oil can undergo significant variations in relation to the process canning and to the storage. Particularly; the values of the parameter K270 can undergo a notable increase and the limits prescribed by E.E.C. regulation n. 2568/91 are no already respected after the sterilization, the most important phase of the industrial process technology. The technological impact caused variation of the sterol composition, in particular regarding to the delta7-stigmastenol contents that undergo probably in relation to the interchange with sterols of the vegetables and to the canning process, while the trans fatty acids content remains, in the considered ageing time, within the virgin olive oils E.E.C. limits in spite of the drastic manufacturing conditions. Therefore the analysis of the trans isomers of unsaturated fatty acids, together with other parameters, can be useful to verify the genuinity of extra virgin olive oil in vegetables canned in glass.
Authors Cresti M; Linskens HF; Mulcahy DL; Bush S; Stilio VD; Xu MY; Vignani R; Cimato A
Title Preliminary Communication about the Identification of DNA in Leaves and in Olive Oil of Olea europaea
Journal Olivæ, 69, 36-37
Keywords DNA fingerprinting; Olea europaea; RAPDs;
Abstract RAPDs-fingerprinting was used to differentiative 9 0live genotypes from central Italy (Tuscany and Liguria); OPA-09 and OPA-13 both generated a high degree of polymorphism in all samples. DNA markers were evidenciated by agarose-gel electrophoresis and ethidiumbromide staining. In parallel DNA was extracted from monovarietal oil sediments, subjected to RAPD-PCR amplification and subsequently compared to the leaf fingerprint belonging to the same cultivar: DNA marker profiles of amplified samples of oil and leaf extracts obtained with primer OPA-90 from genotype Grossolana showed a high degree of similarity.
Authors Stefanoudaki E; Kotsifaki F; Koutsaftakis A
Title The potential of HPLC triglyceride profiles for the classification of Cretan olive oils
Journal Food Chemistry, 60, 425-432
Keywords classification; HPLC; olive oil;
Abstract One hundred and twenty authentic olive oil samples of the two major Cretan olive cultivars, Koroneiki and Mastoidis, collected at different maturity stages have been obtained from different producing areas and analysed by isocratic high-performance liquid chromatography according to the official EC method. Multivariate analysis, including principal component analysis and canonical discrimination analysis, were used to characterize the oils according to cultivar, location and sampling date. Using the triglyceride compositional data, the two varieties examined were sufficiently separated by means of discriminant analysis procedures. Within each variety the oils were grouped quite clearly according to their geographic origin. Samples that originated from neighbouring locations with no marked differences in geographic morphology, or samples from locations with some extremes in the climatic conditions, presented some discrepancies in classification.
Authors Gomes T; Caponio F
Title Evaluation of the State of Oxidation of Crude Olive-Pomace Oils. Influence of Olive-Pomace Drying and Oil Extraction with Solvent
Journal Journal of Agricultural and Food Chemistry, 45, 1381-1384
Keywords triglyceride oligopolymers; oxidized triglycerides; partial glycerides; olive pomace; crude pomace
Abstract The aim of this investigation was to follow the progress of oxidation during the phases of the industrial process of olive -pomace drying and the subsequent step of crude pomace oil extraction with solvent. Silica-gel column chromatography and high-performance size-excusion chromatography were the analytical techniques utilized to this purpose. The data obtained showed that most of the oxidation occurs during industrial drying of the pomace with a mean increase of 35% in the oxidized triglycerides while no statistically significant increase was observed for triglyceride oligopolymers. The subsequent extraction of oil with solvent and the removal of the last traces of commercial hexane for the preparation of crude olive-pomace oil did not seem to entail any substantial increase in oxidation. There was a change in the state of oxidation given that there was an increase in triglyceride oligopolymers; which on average reached 0.32%, and in secondary oxidation products (mean p-anisidine value =15.31).Hydrolytic degradation of crude pomace oils was particularly high with a mean value of free fatty acids of 9.24% and of diglycerides of 5.75%.
Authors Tous J; Romero A; Plana J; Guerrero L; Díaz I; Hermoso F
Title Características de los Aceites de Oliva Virgen de la Variedad 'Arbequina'
Journal Fruticultura Profesional, 88, 118-124
Keywords Arbequina “Sensory Analysis”;
Abstract Dentro de los aceites de oliva vírgenes de calidad que se producen en España; Cataluña destaca por tener dos Denominaciones de Origen (Garrigues y Siurana) de las seis actualmente existentes. La producción de aceite de virgen extra de las mismas procede de la variedad Arbequina, aproximadamente 8.000 tm, repartidas entre las D.O.Garrigues, en Lleida 5.000tm), y Siurana en Tarragona (3.000 tm). Estos aceites son muy apreciados tanto a nivel nacional como internacional por sus excelentes características organolépticas. En los últimos años, esta variedad se está extendiendo por España (Andalucía, Aragón, etc.,) y otros países del mundo (Argentina).
Se estudian las características físico- químicas y sensoriales de los aceites de oliva vírgenes de la variedad Arbequina producidos, principalmente, en Cataluña, Andalucía y Aragón. Los resultados preliminares obtenidos indican que algunos parámetros del aceite de Arbequina varían significativamente al cultivarla en diferentes medios agrologicos, principalmente determinados ácidos grasos, polifenoles estabilidad y algunos atributos sensoriales del aceite.
Authors Alonso L; Fontecha J; Lozada L; Juárez M
Title Determination of Mixtures in Vegetables Oils and Milk Fat by Analysis of Sterol Fraction by Gas Chromatography
Journal Journal of the American Oil Chemists Society, 74, 131-135
Keywords Adulteration; Methyl esters; milk fat; olive oil; palm oil; sterols; sunflower oil; unsaponifiable; vegetable oil; capillary gas-chromatographic analysis;
Abstract A rapid gas-chromatographic (GC) procedure was developed for the analysis of the total sterol fraction of vegetable oils; milk fat or mixtures, to detect possible admixtures of sunflower with olive oil and the addition of vegetable oils to milk fat. The method, which employs alkali-catalyzed transesterification with KOH/methanol, was compared with saponification procedures with and without transformation of sterols into silyl derivatives prior to analysis. Repeatability of the method was assessed, and the coefficient of variation was 6.0 and 8.0% for b-sitosterol in olive and sunflower oils, respectively. Recovery of b-sitosterol ranged from 92.6 to 95.8 for both oils. The GC method assayed in this work requires little analysis time and eliminates the need for saponification, extraction, and derivatization steps. It offers good repeatability and recovery and is thus well suited to routine use.
Authors Frega G; Caglioti L; Mozzon M
Title Composizione chimica e parametri di qualitá degli oli estratti da olive snocciolate
Journal Rivista Italiana delle Sostanze Grasse, 74, 241-245
Abstract The present paper is a first approach to the study of the chemical composition and quality parameters of olive oils obtained by a new technology that involves the separation of stones from the entire fruits before oil extraction.The quality parameters; the sensorial analysis (Panel Test), the GC-MS of volatile constituents, the composition of unsaponifiable fractions, and the oxidative stability (Rancimat Test) of olive oils obtained from the same fruits by two different methods of extraction (traditional milling of stoned olives) has been compared. Our studies show, for the oils obtained a greater oxidative stability and better organoleptic than for the oils obtained by the traditional milling of entire fruits.
Authors Ruiz del Castillo ML; Caja MM; Herraiz M; Blanch GP
Title Rapid Recognition of Olive Oil Adulterated with Hazelnut Oil by Direct Analysis of the Enantiomeric Composition of Filbertone
Journal Journal of Agricultural and Food Chemistry, 46, 5128-5131
Keywords Adulteration; hazelnut oil; olive oil; on-line coupling RPLC-GC;
Abstract On -line coupling of reversed-phase liquid chromatography to gas cromatography (RPLG-GC) using a programmable temperature vaporizer (PTV) as an interface is used for detecting adulteration of hazelnut oil in olive oil on the basis of the determination of the enantiomeric composition of (E)-5-methylhept- 2-en-4-one (filbertone). Different variables (i.e.; packing material used for trapping the LC-GC transferred solutes, desorption temperature, and eluent composition of the mobile phase during the LC preseparation) are investigated in terms of their influence on the sensitivity achievable in the RPLC-GC analysis. The method does not require any type of sample pretreatment, thus allowing the direct and rapid analysis (under 50 min) of samples oils Working under the experimental conditions proposed, adulterations of olive oils with hazelnut oil percentages lower than 5% are detectable.
Authors Sacchi R; Mannina L; Fiordiponti P; Barone P; Paolillo L; Patumi M; Segre AL
Title Characterization of Italian Extra Virgin Olive Oils Using 1H-NMR Spectroscopy
Journal Journal of Agricultural and Food Chemistry, 46, 3947-3951
Keywords authentication; geographical origin; hierarchical clustering; Olive variety; Proton NMR spectroscopy; Virgin olive oil;
Abstract High-field (600-MHz) proton nuclear magnetic resonance (1H-NMR) spectroscopy was applied to the analysis of 55 extra virgin olive oil samples from four Italian regions (Campania; Lazio, Sicily, and Umbria) and obtained from different olive varieties. The multivariate statistical analysis (PCA, hierarchical clustering) performed on the normalized intensities of 1H-NMR resonances due to minor components (beta-sitosterol, n-alkenals, trans-2-alkenals, and other volatile compounds) allows a good classification of oil samples obtained from traditional varieties with respect to the region of origin (96% of oils correctly classified). Samples obtained from one new experimental cultivar (FS-17) were not correctly classified, indicating a strong contribution of olive variety on the chemical composition of virgin olive oils. The potential contribution and limits of NMR in the authentication of virgin olive oil geographical origin and variety are discussed.
Authors Aparicio López R; Morales MT
Title Characterization of Olive Ripeness by Green Aroma Compounds of Virgin Olive Oil
Journal Journal of Agricultural and Food Chemistry, 46, 1116-1122
Keywords fuzzy logic; green sensory note; Olea europea L; ripeness; statistics; Virgin olive oil; volatiles;
Abstract The evolution of the volatile compounds responsible for virgin olive oil green aroma has been studied in samples obtained from four olive fruit varieties (Arbequina and Picual; Spain; Koroneiki, Greece; and Coratina, Italy), picked at three different stages of ripeness during two consecutive crops. The volatile compounds hexanal, (E)-3-hexenal,(Z)-3-hexenal,(E)-2-hexenal, hexyl acetate (Z)-3-hexenyl acetate,hexan-1-ol,(E)-3-hexen-1-ol,(Z)-3-hexen-1-ol,and (E)-2-hexen-1-ol were considered in this study. The sensory significance of these volatile compounds has been stated by their odor activity value (OAV), while their synergic relationships with green sensory attributes have been analyzed by principal components analysis. The stages of ripeness of each variety, with the whole set of volatile compounds, were characterized by cluster analysis. Detailed information corresponding to each volatile compound for each stage of ripeness, after fuzzy filtering of the quantitative data, has also been established. Alcohols produced from linolenic acid (E)-3-hexen-1-ol, (Z)-3-hexen-1-ol, and (E)-2-hexen-1ol, and hexanal and hexyl acetate-both produced from linoleic acid-are major contributors to the ripeness characterization. The results were verified by applying multiple regression to the quantitative values of volatile compounds of a test set of eight Arbequina samples picked each fortnight from unripened to over-ripened olives. From the results of this study it can be concluded that the unripe stage is the best characterized, although the result in prediction for three stages of ripeness was an adjusted R2 value of 0.98.
Authors Williams M; Morales MT; Aparicio López R; Harwood JL
Title Analysis of Volatiles from Callus Cultures of olive Olea Europaea
Journal Phytochemistry, 47, 1253-1259
Keywords acyl composition; callus; lipoxigenase pathway; Olea europaea; Oleaceae; olive; volatiles;
Abstract The lipoxigenase pathway in olive fruit gives rise to volatile products which influence the aroma of the harvested oil. In this study dynamic headspace gas chromatography was used in order to investigate volatile production by different olive cultivars. Olive callus cultures were used as a model for this purpose; because of the ease of standardizing the growth conditions of the calli compared to working with field-grown material. The cultures contained substantial amounts of the polyunsaturated fatty acids, linoleate and a-linolenate, which are the normal substrates for lipoxygenases. Most of the major volatiles that characterize virgin olive oil were also produced by the cultures, especially the unsaturated and saturated C6 aldehydes, alcohols and their acetyl esters. Moreover, BY means of ANOVA test, a strong effect of cultivar on volatile production in olive cultures was clearly established. This agreed with data for olive oils from different cultivars, which are also easily distinguished by headspace gas liquid chromatography. We have also demonstrated that changing the culture conditions for temperature an pH produced qualitative and quantitative alterations in volatile production.
Authors Angerosa F; Camera L; D'Alessandro N; Mellerio G
Title Characterization of Seven New Hydrocarbon Compounds Present in the Aroma of Virgin Olive Oils
Journal Journal of Agricultural and Food Chemistry, 46, 648-653
Keywords Flavor; lipoxigenase; pentene dimers; radical coupling; Virgin olive oil;
Abstract Seven isomeric hydrocarbons were detected in the volatile fraction of three samples of virgin olive oil. Chemical ionization mass spectrometry was used to assign the molecular formulas. Their structures were confirmed by comparison of retention time and mass spectral data with those of a synthetic sample obtained by pentene radical coupling. A final characterization of each chromatographic peak was done by means of a chiral capillary column to distinguish the optically active compounds from the isomers without chiral centers. For the quantitation the recovery factor in the oily matrix during the extraction of the volatile fraction was obtained using a related chemical; the commercially available b-citronellene. On the basis of the previous literature and the present experiments a tentative rationalization of the involved biochemical pathway is proposed.
Authors Mariani C
Title Sulla presenza di ergosterolo negli oli di oliva
Journal Rivista Italiana delle Sostanze Grasse, 75, 3-10
Keywords ergosterol; sterols; olive oil;
Abstract Various grades of crude olive oil and of commercial olive oils were analyzed by GC and GC/MS for contents of sterols. In addition to sitosterol; the main sterol, the samples also contained ergosterol and several unknown sterols, 1 of which appeared to be ergosterol with unsaturation in the cyclopentanperidrophanantrenic nucleus. Identification was difficult as this sterol was eluted close to the brassicasterol under normal analytical conditions. It is concluded that in olive oils containing greater than 0.1% brassicasterol in the sterol fraction, correct interpretation of the findings requires varied analytical techniques.
Authors Gomes T; Caponio F; Baiano A; De Pilli T
Title Misura della degradazione ossidativa ed idrolitica di olio di oliva utilizzato come copertura in conserve alimentari
Journal Rivista Italiana delle Sostanze Grasse, 75, 7-82
Keywords hydrolytic degradation of olive oil;
Abstract Thirty commercial samples of vegetables and fish preserved in olive oil or extra virgin olive oil were examined to assess the oxidative and hydrolytic degradation of the oils used and their genuineness.
Silica-gel column and high-performance size-exclusion chromatography were performed along with the routine analyses. The results obtained showed that triglyceride oligopolymers were present in all the oil samples analyzed. For the extra virgin oliye oils this was probably due to the effect of the thermal stabilisation procedures and the times of storage. The amounts were however quite low and averaged 0.18%, SD=0.06. The overall oxidation of the olive oil (refined plus virgin) used to cover the preserved foodstuff was assessed on the basis of the oxidised triglyceride and oligopolymer levels. It was greater in the fish preserves with an average value of 2.65% (SD=1.71) while the vegetable preserves had an average value of 1.96% (SD=0.55). The hydrolytic degradation of the olive oils used in the preserved food was measured by determining the amounts of diglycerides present. On average, the values were quite similar for the fish preserves (3.57%, SD=0.57) and the vegetable preserves (3.60%, SD=0.25).
Authors Spangenberg JE; Macko SA; Hunziker J
Title Characterization of Olive Oil by Carbon Isotope Analysis of Individual Fatty Acids: Implications for Authentication
Journal Journal of Agricultural and Food Chemistry, 46, 4179-4184
Keywords adulterations; carbon isotope; fatty acids; isotopic characterization; olive oil;
Abstract The fatty acids of olive oils of distinct quality grade from the most important European Union (EU) producer countries were chemically and isotopically characterized. The analytical approach utilized combined capillary column gas chromatography-mass spectrometry (GC/MS) and the novel technique of compound-specific isotope analysis (CSIA) through gas chromatography coupled to a stable isotope ratio mass spectrometer (IRMS) via a combustion (C) interface (GC/C/IRMS). This approach provides further insights into the control of the purity and geographical origin of oils sold as cold-pressed extra virgin olive oil with certified origin appellation. The results indicate that substantial enrichment in heavy carbon isotope (13C) of the bulk oil and of individual fatty acids are related to (1) a thermally induced degradation due to deodorization or steam washing of the olive oils and (2) the potential blend with refined olive oil or other vegetable oils. The interpretation of the data is based on principal component analysis of the fatty acids concentrations and isotopic data (13Coil, 13C16:0, 13C18:1) and on the 13C16:0 vs 13C18:1 covariations. The differences in the 13C values of palmitic and oleic acids are discussed in terms of biosynthesis of these acids in the plant tissue and admixture of distinct oils.
Authors Baeten V; Hourant P; Morales MT; Aparicio López R
Title Oil and Fat Classification by FT-Raman Spectroscopy
Journal Journal of Agricultural and Food Chemistry, 46, 2638-2646
Keywords chemometrics; FT-Raman spectroscopy; oils and fats;
Abstract One hundred and thirty-eight edible oil and fat samples from 21 different sources; either vegetable (Brazil nut, coconut, corn, high oleic sunflower, olive oil, peanut, palm, palm kernel, rapeseed, soybean, sunflower, etc.) or animal (butter, hydrogenated fish, and tallow) have been analyzed. The spectral features of the most noteworthy bands are studied, and their correlations with the amount of fatty acids quantified by gas chromatography are presented. Principal component analysis is applied to classify the set of samples by their level of unsaturation [saturated (SFA),monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA).The most remarkable MUFA and PUFA oil sources are independently classified by applying stepwise linear discriminant analysis to the Raman shifts selected by their correlation with fatty acids or structural assignments. The results show that FT-Raman spectra not only have information of the degree of unsaturation but also of the balance among the amounts of SFA,MUFA, and PUFA. The scattering intensities near different Raman shifts (3013, 1663, and 1264 cm-1) show high correlations with the fatty acid profile determined by gas chromatography.
Authors Ibrik A; Chahinian R; Sarda L; Comeau L
Title Biochemical and Structural Characterization of Triacylglycerol Lipase from Penicillium cyclopium
Journal Lipids, 33, 377-384
Keywords Characterization; lipase; triacylglycerol;
Abstract An extracellular lipase; active on water- insoluble triacylglycerols, has been isolated from Penicillium cyclopium. The purified enzyme has a molecular mass of 29 kDa by gel filtration and SDS-polyacrylamide gel electrophoresis. It hydrolyzes emulsions of tributyrin, trioctanoin, and olive oil at the same rate as pancreatic lipase and shows very low activity against partial acylglycerols (monooctanoin and dioctanoin) and methyl esters. It is stable at 35º C for 60 min and has maximal activity in a pH range of 8--10. Hydrolysis of triacylglycerols by P.cyclopium lipase is inhibited by detergents such as Triton X-100. Comparison of the sequence of the 20 first amino acid residues of P. cyclopium triacylglycerol lipase with other Penicillium lipases indicates a high homology with previously characterized lipases produced by P.expansum and P. solitum which are enzymes of comparable size and substrate specificity. Conversely, homology between P. cyclopium lipase and P.simplicissimum lipase, a nonspecific lipolytic enzyme, is low. Penicillium cyclopium triacylglycerol lipase shows no homology with P. camembertii lipase which is specific to monoacylglycerol and diacylglycerol.
Authors Pirisi FM; Angioni A; Bandino G; Cabras P; Guillou C; Maccioni E; Reniero F
Title Photolysis of a-tocopherol in Olive Oils and Model Systems
Journal Journal of Agricultural and Food Chemistry, 46, 4529-4533
Keywords olive oil; photolysis; α-tocopherol;
Abstract The photolysis of a-tocopherol (I) in olive oil (O) and in some model systems (n-hexane = H; anhydrous n-hexane = HA; and triolein = T) was studied under sunlight and under artificial light (l > 290 nm) by HPLC and GC/MS. In O and T, I disappeared linearly to 50% of the starting concentration, reached constant value, and finally disappeared rapidly from the medium. In the model system, photolysis followed a pseudo-first-order kinetics. Although no peacks attributable to photoproducts were found inO, a main product identified by 1H and 13C NMR and GC/MS as 5-formyltocopherol (II) was found in the model systems. Irradiation of compound IIled to species undectable by HPLC in agreement with a slower consecutive kinetic process than that of I. In the HA and T systems, the formation of II occurred at lower levels than in H. The possible behavior of photodegradation is discussed.
Authors Fedeli E; Cortesi N; Provellini P
Title L,analisi trigliceridica mediante HPLC nell,individuazione di commistioni di oli di seme ad alto contenuto in oleico con oli di oliva
Journal Rivista Italiana delle Sostanze Grasse, 75, 483-489
Abstract The result of a careful statistical analysis on about 200 samples of olive oils of different and reliable sources has allowed to develop a method of investigation based on the triglycerydes analysis able to detect mixtures of monounsaturated seed oils in olive oils.
Authors Amelio M; Rizzo R; Varazini F
Title Separation of Stigmasta-3,5-diene, Squalene Isomers, and Wax Esters from Olive by Single High-Performance Liquid Chromatography Run
Journal Journal of the American Oil Chemists Society, 75, 527-530
Keywords EC regulations; HPLC; HRGC; olive oils; squalene isomers; stigmasta-3;5-diene; wax esters;
Abstract To ascertain the authenticity of olive oils the European Community Regulation requires the stigmasta-3;5-diene and wax ester contents to be determined. The official methods are time- consuming and not suitable for many daily analyses, as quality-control laboratories need. A method is presented here that allows single high- performance liquid chromatography separation of stigmatasa -3,5-diene and was esters, as well as of the squalene isomers, which give further information on the oil's authenticity. For stigmatasa-3,5-diene, the comparison with results obtained with the official method is good. Also for wax esters, the agreement was good, even if they were compared with results obtained from a quicker method as reliable as the official one. The possibility of separating the squalene isomers also at the same time makes the proposed method more advantageous. On the whole, the method, which is suggested for routine and quick screening but not for the exact evaluation of the analyte contents, seems to be a convenient choice for ascertaining on a daily basis the samples’ legal compliance (i.e., whether the analyte content is or is not below the legal value).
Authors Favier JP; Bicanic D; Cozijnsen J; Veldhuizen Bv; Helander P
Title CO2 Laser Infrared Optothermal Spectroscopy for Quantitative Adulteration Studies in Binary Mixtures of Extra-Virgin Olive Oil.
Journal Journal of the American Oil Chemists Society, 75, 359-362
Keywords Adulteration; infrared; olive oil; optothermal; photoacoustic spectroscopy; spectroscopy;
Abstract Optothermal widow spectroscopy at CO2 laser infrared wavelengths was used to detect the exent of adulteration of extra-virgin olive oil by sunflower and safflower oils. A good linearity between the strength of optothermal signal and the concentration of each adulterating compound was found. Predicted limits of detection presently attainable by this new method are 6 (w/w) and 4.5 (w/w) for extra-virgin olive oil adulterated with safflower oil and sunflower oil; respectively, and were confirmed experimentally; the corresponding relative errors were 0.3 and 0.18 %. Interference effects are comparable to those encountered in other spectroscopic methods at the same wavelength.
Authors Blanch GP; Caja MM; Ruiz del Castillo ML; Herraiz M
Title Comparison of Different Methods for the Evaluation of the Authenticity of Olive Oil and Hazelnut
Journal Journal of Agricultural and Food Chemistry, 46, 3153-3157
Keywords Adulteration; filbertone; hazelnut oil; olive oil;
Abstract Different methods for the analysis of hazelnut oil and olive oil are compared in terms of the potential of each procedure in detecting compositional differences for evaluation of authenticity. These methods involve the use of different sample preparation techniques; namely simultaneous distillation-extraction (SDE) and supercritical fluid extraction (SFE), and the subsequent analysis by capillary gas chromatography using a programmable temperature vaporizer (PTV). On--line coupling of reversed--phase liquid chromatography to gas chromatography (RPLC-GC) was also considered for the analysis of the samples investigated. Working under the experimental conditions proposed, identification of olive oil, hazelnut oil, and mixtures of both oils (85:15) may be possible on the basis of the determination of the presence or absence of (E)-5-methylhept-2-en-4-one (filbertone).
Authors Morchio G; Pellegrino A; Mariani C; Bellan G
Title Sulla possibilitá di individuare l'olio di nocciola nell'olio di oliva. Nota 2
Journal Rivista Italiana delle Sostanze Grasse, 76, 115-127
Keywords hazelnut oil;
Abstract The compositional characteristics of hazelnut oil are very close to those of olive oil; meaning that it can be mixed without interfering with the usual analytical parameters. For this reason we focused our attention on the study of the minor components, in particular the tocopherols. an experimental study was set up with both HPLC/GC techniques. An aliquot of the unsaponifiable matter was extracted from the olive oil samples and was analyzed by HPLC. The two fractions left, gamma + beta and delta tocopherol were then analyzed by GC.In genuine olive oil, the reference values of delta and gamma tocopherol are respectively lower than 0.05 mg% and 0.8 mg% and the ratio between beta/delta is higher than 4.5. In hazelnut oil the values of delta and gamma tocopherol are about 0.4 and 7.0 mg% respectively, and the ratio between beta/delta is lower than 4.5. Therefore, the tocopherol content of hazelnut oil is ten times higher than that present in olive oil, so if 10% hazelnut oil were added to olive oil, so if 10% hazelnut oil were added to olive oil, it would appear that the gamma and delta tocopherol values would be doubled. Our study was made on a large of samples, and for varietal and other reasons, some of the genuine olive oils had the gamma, delta tocopherol and the ratio beta/delta unlike the values normally associated with genuine olive oil. From our experimental data, if one of the three parameters, or more rarely all of them simultaneously result positive, the samples should undergo the determination of the esterified sterols in order to confirm whether they are genuine. For pomace oil, values of gamma tocopherol values never go above this figure in genuine pomace oil.
Authors Aparicio López R; Roda L; Albi MA; Gutiérrez F
Title Effect of Various Compounds on Virgin Olive Oil Stability Measured by Rancimat
Journal Journal of Agricultural and Food Chemistry, 47, 4150-4155
Keywords antioxidant activity; carotenoids; chemometrics; fatty acids; phenols; tocopherols; Virgin olive oil;
Abstract Phenolic and ortodiphenolic compounds together with carotenoids tocopherols; pigments, and fatty acids were tested for their antioxidant effect in 79 samples of virgin olive oils cv. Picual and Hojiblanca. A linear regression based on the oleic/linoleic ratio and the contents of phenols and tocopherols showed a good correlation (adjusted-R2=0,91)with the stability measured by Rancimat, later verified with an external text set (adjusted-R2=0,95) A tentative study on the percentage contribution of each chemical variable to stability is discussed. The contribution of phenolic and ortodiphenolic compounds was around 51% the composition of fatty acids 24%, and in less percentage a-tocopherol, carotenoids and chlorophylls. No effect, or very little, was shown by b-and g-tocopherols.
Authors Angerosa F; Bréas O; Contento S; Guillou C; Reniero F; Sada E
Title Application of stable Isotope Ratio Analysis to the Characterization of the Geographical Origin of Olive Oil
Journal Journal of Agricultural and Food Chemistry, 47, 1013-1017
Keywords Carbon and oxygen stable isotopes; geographical origin; olive oil;
Abstract To gain information about the Geographical origin of oil samples; measurements of d13C and d18O of the whole oil and some of its fractions have been performed on samples coming from fruits of Olea europaea. L. produced in Greece, Morocco, Spain, Italy, Tunisia and Turkey. The results obtained by applying statistical procedures have given pieces of evidence that oil sample have shown the trend to cluster according to the different climatic areas of growing environment of fruits. Some confusion has been observed for samples coming from neighboring countries having similar climates.
Authors Mannina L; Patumi M; Fiordiponti P; Emanuele MC; Segre AL
Title Olive and Hazelnut Oils: a Study by High-Field 1H NMR and Gas Chromatography.
Journal Journal of Food Science, 2, 139-149
Abstract High-field Nuclear Magnetic Resonance (NMR) and Gas Chromatography (GC) were used to analyze hazelnut and olive oils in order to evaluate the possibility of detecting hazelnut oil present in adulterated olive oil samples. The fatty acid composition of hazelnut oil was carefully determined and compared with the fatty acid composition of extra virgin olive oil. Linolenic acid content and volatile aldehydes present only in non deodorized hazelnut oils were easily detected with NMR. If the content of linolenic acid was lower than o.5% or if anomalous aldehydes were present. a full gas chromatographic analysis was performed. Different olive-hazelnut oil mixtures were prepared and analyzed by gas chromatography. Linear Discriminant Analysis (LDA) was used to analyze the GC results.
Authors Salas J; Sánchez J
Title The Decrease of Virgin Olive Oil Flavor Producer by High Malaxation Temperature Is Due to Inactivation of Hydroperoxide Lyase
Journal Journal of Agricultural and Food Chemistry, 47, 809-812
Keywords Aroma; hydroperoxide lyase; lipoxigenase; malaxation temperature; olive oil;
Authors Ranalli A; Ferrante ML; De Mattia G; Costantini N
Title Analytical Evaluation of Virgin Olive Oil of First and Second Extraction
Journal Journal of Agricultural and Food Chemistry, 47, 417-424
Keywords flavour; Olive processing; percolation-centrifugation technology; quality and genuineness characteristics of products; shelf life; yields;
Abstract Virgin olive from percolation (firs extraction) have been compared with the corresponding oils from centrifugation (second extraction) The former characterized by (i) higher contents of total phenols; 0-diphenols, hydroxytyrosol, tirosol-aglycons, tocopherols, trans-2-hexenal, total volatiles, and waxes; (ii) higher values of resistance to autoxidation and of turbidity; (iii) higher sensory scores; (iv) higher ratios of campesterol/stigmasterol, trans-2-hexenal/hexenal, and trans -2-hexenal/total volatiles; (v) lower contents of chlorophylls, pheophytins, sterols, and aliphatic and triterpene alcohols; (vi) lower alcoholic index and color indices; (vii) similar percentages of acidity, peroxide index, and UV (ultraviolet) spectrometric indices; (viii) similar percentages of saturated and unsaturated fatty acids, triglycerides, and diglycerides; Nd (ix) similar values of glyceridic indices. Stigmastadienes, trans-oleic, trans-linoleic and trans-linolenic acid isomers were not detected in the two genuine oil kinds. Hence, the qualitative levels of the firs extraction superior to the second extraction one.
Authors Mariani C; Bellan G; Morchio G; Pellegrino A
Title I componenti minori liberi ed esterificati dell'olio di oliva e dell´olio di nocciola: loro possibile utilizzo nell'individuazione di commistioni.Nota 3
Journal Rivista Italiana delle Sostanze Grasse, 76, 297-305
Keywords diterpenic ester; esterification; hazelnut;
Abstract In studies to improve the accuracy of an identification method; based on the increasing ratio of gamma- to beta-tocopherols in blends of hazelnut and olive oils [see FSTA (1999) 31 9Ne553], the effect of minor components, specifically free and esterified sterols, were taken into consideration. In hazelnut oil, which contains more campesterol and Delta-7-stigmastenol (Delta-7-S) than olive oil, the ratio of Delta-7-S to Delta-7-avenasterol (Delta-7-A) is always greater than 1, but always less than 1 in olive oil. To amplify this difference, the sterol ester fraction was separated out, saponified and analyzed by GC, from the results of which a ratio was derived relating the campesterol and Delta-7-A contents, namely campesterol x (Delta-7-A)/Delta-7-A. As both compounds are always higher in hazelnut than in olive oil, a ratio greater than 1 indicates presence of the former. The findings were confirmed by analysis of olive oil samples with and without added hazelnut oil. [See FSTA (1999) 31 10Ne605 for part II.]
Authors Nota G; Naviglio D; Romano R; Sabia V
Title Determination of the Wax Ester Content in Olive Oils. Improvement in the Method Proposed by EEC Regulation 183/93.
Journal Journal of Agricultural and Food Chemistry, 47, 202-205
Keywords GC; olive oils; solid-phase extraction; wax;
Abstract A simpler and faster procedure than the official one described in document IV of European Economic Community Regulation 183/93 is proposed. The wax ester fraction is isolated from triglycerides using a commercially available silica gel column and carbon tetrachloride as eluent. The recovered wax ester fraction; with the addition of a suitable internal standard solution, is analyzed by gas chromatography. A column with a 65% phenyl methyl silicone stationary phase allows a satisfying separation of wax ester fraction in comparison with both a sterol ester and a light fraction eluted before the internal standard. Furthermore, also the single components of the wax ester fraction are suitable separated.
Authors Morales MT; Angerosa F; Aparicio R
Title Effect of the extraction conditions of virgin olive oil on the lipoxigenase cascade: Chemical and sensory implications
Journal Grasas y Aceites, 50, 114-121
Keywords extraction systems; lipoxigenase (cascade); Virgin olive oil; volatile compounds;
Abstract The volatile compounds produced through the lipoxigenase cascade are responsible for the most remarkable sensory attributes of virgin olive oil. The paper analyses the evolution of these compounds according to different conditions of temperature and time of the malaxing process. The influence of these parameters on the production of C6 and C5 volatile compounds is stated together with the effect that the amount of these compounds has on the most remarkable virgin olive oil sensory descriptors (green; bitter-pungent, sweet and undesiderable). Optima values of temperature and time are given for producing high sensory quality virgin olive oils. Three cultivars, Spanish Picual and Italian Frantoio and Coratina, were characterized by sensory attributes and volatile compounds quantified by two different methodologies in order to avoid that results could be circumscribed to a specific cultivar or a quantification method.
Authors Royer A; Gerard C; Naulet N; Lees M; Martín GJ
Title Stable Isotope Characterization of Olive Oils. I- Compositional and Carbon-13 Profiles of Fatty
Journal Journal of the American Oil Chemists Society, 76, 357-363
Keywords Composition; fatty acids; IRMS; isotope ratios; olive oil;
Abstract Nearly 200 olive oils produced in the Mediterranean basin; mainly in Greece, during 4 yr from 1993 to 1996, were studied by gas chromatography (GC) and on-line GC-isotope ratio mass spectrometry (GC-C-IRMS). The composition of the oils in the more abundant fatty acids (C16:0, C16:1, C18:0, C18:1, C18:2 and C18:3) was obtained by GC after transesterification of the triglycerides into methyl esters. Using the hyphenated GC-C-IRMS technique, the 13C contents of the three most abundant acids, C16:0, C18:1 and C18:2 were measured with satisfactory accuracy. The results, analyzed in terms of geographical, temporal, and botanical factors, provide new criteria for the authentication of olive oils.
Authors Royer A; Naulet N; Mabon F; Lees M; Martín GJ
Title Stable Isotope Characterization of Olive Oils. II- Deuterium Distribution in Fatty Acids Studied by Nuclear Magnetic Resonance
Journal Journal of the American Oil Chemists Society, 76, 365-373
Keywords deuterium; fatty acids; isotope ratios; olive oil; SNIF-NMR;
Abstract Site-specific isotope fractionation of hydrogen was investigated; at natural abundance, by deuterium nuclear magnetic resonance (SNIF-NMR) on nearly 200 olive oil samples. Owing to the complexity of the 2H NMR spectra of the mixtures of fatty acids obtained after hydrolysis of the oils, the different signals were gathered into six clusters. By knowing the contribution to the clusters. By knowing the contribution to the clusters of each of the four fatty acids considered (C16:0, C18:0, C18:1 and C18:2) and the composition of the fatty acids in the mixture, it is possible to compute the site-specific isotope ratios of the clusters from the molar fractions obtained from the 2H NMR-spectra and from the total isotope ratio of the mixture, determined by isotope ratio mass spectrometry. The results are discussed in terms of geographical (country, region, and elevation) and temporal (year) parameters and they are tentatively explained on a climatic basis.
Authors Kiritsakis AK
Title Flavor Components of Olive Oil: A Review
Journal Journal of the American Oil Chemists Society, 75, 673-681
Keywords 2-heptenal; enzymatic process; flavor components; hexanal; maturity stage; off-flavor; olive fruit; polyphenols; Sensory quality; trans-2-hexanal; volatile components;
Authors Mariani C; Bellan G; Morchio G; Pellegrino A
Title I componenti minori liberi ed esterificati dell'olio di oliva e dell'olio di nocciola: loro possibile utilizzo nell'individuazione de commistioni. Nota 1
Journal Rivista Italiana delle Sostanze Grasse, 76, 59-67
Keywords hazelnut oil;
Abstract Adulteration of olive oil can be determined by checking parameters such as triglyceride composition; sterols and newly formed steroid hydrocarbons; however, detection of oils similar to olive oil, such as hazelnut oil, in oil mixtures is difficult. Olive oil contains a higher percentage of beta-tocopherol than gamma-tocopherol in comparison to hazelnut oil, while hazelnut oil has a higher content of delta-tocopherol than olive oil which contains only trace amounts. There is also a difference in the composition of diterpenic esters and sterol esters in the 2 oils. It is concluded that it is possible to detect addition of hazelnut oil to olive oil by comparing tocopherol fractions.
Authors Blanch GP; Caja MM; León M; Herraiz M
Title Determination of (E)-5-methylhept-2-en-4-one in deodorized hazelnut oil. Application to the detection of adulterated olive oils
Journal Journal of the Science of Food and Agriculture, 80, 140-144
Keywords Adulteration; Deodorization; enantiomeric analysis; hazelnut oil; olive oil;
Abstract The presence of (E)-5-methylhept-2en-4-one (filbertone) in a hazelnut oil; deodorized in a laboratory system using nitrogen as stripping gas, is studied regarding its usefulness as a chiral marker for detecting adulterations of olive oil. The analytical method involves the use of both simultaneous distillation--solvent extraction as a sample concentration step and a chiral stationary phase in the subsequent gas chromatographic analysis. The procedure in simple, rapid, effective for detecting adulterations of olive oil with hazelnut oil and can reduce falsely negative results obtained if conventional parameters included in current regulations are exclusively considered when establishing purity in olive oils.
Authors Romani A; Minunni M; Mulinacci N; Pinelli P; Vincieri FF
Title Comparison among Differential Pulse Voltametry, Amperometric Biosensor, and HPLC / DAD Analysis for Polyphenol Determination
Journal Journal of Agricultural and Food Chemistry, 48, 1197-1203
Keywords anthocyanins; EGCG; grapes; green tea; olives; polyphenols;
Abstract Polyphenols are widespread in vegetables and fruits. They can play an important role in human diet and health, and they influence the sensorial properties of many foods, and act as natural antioxidants. This study was conducted using HPLC/DAD, tyrosinase biosensor, and differential pulse voltammetry (DPV) analyses to detect polyphenolic compounds in natural complex matrices. The analyses were applied to a series of both standards and natural extracts derived from grape, olives, and green tea. The pure compounds include phenolic acids, flavones, flavonols, catechins, tannins, and oleuropein. HPLC/DAD, DPV, and the biosensor approach were used as independent analytical techniques. Bare graphite screen-printed electrodes were employed in DPV and in the biosensor analysis. The most accurate data were obtained by HPLC/DAD analysis, while the DPV approach using screen-printed electrodes could represent a quick screening method for the determination of polyphenols in natural extracts. Use of the biosensor for the analysis of complex matrices needs further study in order to improve its performance.
Authors Pirisi FM; Cabras P; Falqui Cao C; Migliorini M; Muggelli M
Title Phenolic Compounds in Virgin Oil. 2. Reappraisal of the Extraction, HPLC Separation, and Quantification Procedures
Journal Journal of Agricultural and Food Chemistry, 48, 1191-1196
Keywords HPLC; olive oil; polyphenols; Quantification;
Abstract The extraction procedures (solid/liquid SPE and liquid/liquid LLE) an HPLC separation and quantification methods of polyphenolic compounds have been checked in virgin olive oils in order to explain the differences in content reported in the literature. The work has been carried out on oils prepared from one cultivar and produced under the same protocol. The extraction methods are practically equivalent; but the SPE technique is more favorable because it is faster and simpler. It has been proved that the chromatographic features and the method of chemical expression of the concentrations may greatly affect the final values.Thus, under the same analytical method, the total concentration values of polyphenols of the same oil show variations from 18% to80%, according to the formality of expression as gallic acid, caffeic acid or tyrosol equivalents. The role of the nature and spectrophotometric features of the phenols and of the internal standard is also discussed, and it was found to be an important source of reported variation: A gradient separation with an eluent mixture acetonitrile- sulfuric acid (0.1 mol/L), detection a 225nm, and quantitative calculation of polyphenolic compounds in oils (expressed as Tyrosol equivalents, THYeq) is proposed.
Authors Kiritsakis AK
Title Olive oil : A review
Journal Advances in Food Research, 31, 453-482
Keywords olive oil;
Authors Ruiz del Castillo ML; Herraiz M; Blanch GP
Title Determination of the Enantiomeric Composition of g-Lactones in Edible Oils by On-Line Coupled High Performance Liquid Chromatography and Gas Chromatography
Journal Journal of Agricultural and Food Chemistry, 48, 1186-1190
Keywords edible oils; Enantiomeric composition; lactones; on line RPLC-GC;
Abstract A new method is proposed for the determination of the enantiomeric composition of g-lactones in different vegetable edible oils (i.e.; olive oil, almond oil, hazelnut oil, peanut oil, and walnut oil), and its potential for authenticity control is underlined for a limited of samples. The method is based on the direct injection (i.e., without requiring a sample pretreatment step) in on-line coupled reversed phase liquid chromatography (RPLC-GC) using a chiral stationary phase in the GC-step. Different experimental values for both speed of sample introduction into GC and of the transferred fraction are considered to improve the recoveries obtained. Relative standard deviations lower than 10% and detection limits ranging from 0.06 to 0.22mg/L were achieved for the investigated g-lactones.
Authors Aparicio R; Rocha SM; Delgadillo I; Morales MT
Title Detection of Rancid Defect in Virgin Olive Oil by the Electronic Nose
Journal Journal of Agricultural and Food Chemistry, 48, 853-860
Keywords Electronic nose; sensory evaluation; Virgin olive oil; volatiles: rancidity;
Abstract A sensor array of 32 conducting polymer sensors has been used to detect the rancid defect in virgin olive oils. A training set; composed of admixtures of a Portuguese virgin olive oil with different percentages (0-100%) of a rancid standard oil, was used for the selection of the best sensors classifying correctly the samples. Information on volatile compounds responsible for rancidity and the sensory evaluation of samples by assessors were used for explaining the mathematical selection of sensors. A tentative calibration, using unsupervised procedures (PCA and MDS) and a nonlinear regression, was carried out, with the training set, and later confirmed with a test set with which rancid commercial samples of different varieties were used to spike a Greek extra virgin olive oil at low levels of rancidity (0.5-6%).
Authors Stella R; Barisci JN; Serra G; Wallace GG; De Rossi D
Title Characterization of olive oil by an electronic nose based on conducting polymer sensors
Journal Sensors and Actuators B, 63, 1-9
Keywords Conducting polymer sensors; Electronic nose; food analysis; olive oil;
Abstract The selection and test of an array of conducting polymer sensors with extra-virgin oil samples is presented in this paper as a first step towards the development of an electronic nose dedicated to the detection of olive oil aroma. Different sensors produced by both electrochemical and chemical techniques were initially exposed to a set of pure substances present in the headspace of extra-virgin olive oil and meaningful for the evaluation of its overall organoleptic characteristics. Four sensors showing the best sensitivity to these standard substances were chosen to carry out further experiments on samples of commercial olive oil. Two different experimental set-ups and protocols for olive oil sampling were tested and compared; providing evidence on the best procedure needed to handle this foodstuff and on the possibility of using a dedicated sensing system for practical purposes in the olive oil industry. Three different extra-virgin Italian types of olive oil can be easily distinguished with an array of four sensors and it is possible to detect changes in the aromatic content of the headspace after handling of the samples. Different samples of the same oil show reproducible responses.
Authors Parcerisa J; Casals I; Boatella J; Codony R; Rafecas M
Title Analysis of olive and hazelnut oil mixtures by high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry of triacylglycerols and gas-liquid chromatography of non-saponificale compounds (tocopherols and sterols)
Journal Journal of Chromatography A, 881, 149-158
Keywords food analysis; olive oil; sterols; tocopherols; triacylglycerols; Vitamins;
Abstract We analyzed the triacylglycerol; tocopherol and sterol composition of hazelnut oil, olive oil and their mixtures (90% olive oil with 10% hazelnut oil, 70% olive with 30% hazelnut oil and 50% olive oil with 50% hazelnut oil). The main triacylglycerol were 1,2,3-trioleylglycerol, 2,3-dioleyl-1-palmitoglycerol, 2,3-dioleyl-1-linoleylglicerol and 2,3-dioleyl-1-stearoylglycerol. Non-saponifiable compounds (tocopherols and sterol) were Derivatized as O-trimethylsilyl ethers. a-Tocopherol was the main vitamin E isomer in all samples; however, small amounts of b-tocopherol and y-tocopherol were also found. b-Sitosterol and.5-avanesterol were the principal sterols in all samples; campesterol and stigmasterol were minor sterol compounds in all samples. Obtusifoliol, which was a major sterol in olive and oil mixtures was not found in hazelnut oil. The discriminant analysis showed that hazelnut oil, olive oil and oil mixtures were clearly separated according to their triaglicerol composition.
Authors Ranalli A; Costantini N; De Mattia G; Ferrante ML
Title Evaluating two kinds of centrifuged virgin oils arising from continuous olive processing
Journal Journal of the Science of Food and Agriculture, 80, 673-683
Keywords centrifuged oils; characteristics of by-products; compositional and analytical pattern; continuous olive processing; yield;
Abstract Oils extracted from olive pastes by the direct centrifugation mode were compared with the homologous oils produced by the indirect centrifugation (after percolation) mode. The former were characterized by: (i) higher contents of total phenols; o-diphenols, hydroxytyrosol, Hydroxytyrosol-aglycons, total volatiles, trans-2-hexanal and other pleasant volatiles, total tocopherols, total sterols and wases; (ii) lower contents of triterpene dialcohol, aliphatic and triterpene alcohols, chlorophylls and pheophytins; (iii) lower values of integral color index; (iv) higher values ofturbity, campesterol/stigmasterol ratio, 1,2-diglycerides/1,3diglicerides ratio, oxidative stability and overall quality indices; and (v) higher sensory score. Stigmastadienes and trans-isomer C18 fatty acids were always no detected. The average oil outputs of the two centrifugation extraction procedures were comparable, as confirmed by similar overall ail amounts found in the by-products.
Authors Williams M; Harwood JL
Title Volatile production by the Lipoxigenase Pathway in Olive Callus Cultures
Journal Journal of Experimental Botany, 262-264
Keywords callus culture; lipoxigenase pathway; olive; production; volatile;
Abstract The aroma of an oil derived from the production of the oil's volatile constituents. Some of the major volatiles of olive oil include the derivates of the C6 aliphatic hexanal (1). Of the large of volatiles present; only a few have organoleptic properties which are of any importance. Therefore, the emphasis of analysis has been on identifying only those components with organoleptic properties. We have chosen to use olive cultures as a model to investigate olive production. Callus cultures have already been found to be reliable material to study lipid synthesis as they have an acyl composition compatible with olive volatile production. Callus cultures have already been found to be reliable material to study lipid synthesis as they have an acyl composition compatible with olive fruit (2). The use of cultures is also most useful because it is possible to control strictly the growth conditions of the cultures and hence limit biological variation, while investigating different cultivars.
Authors Vichi S; Pizzale L; Toffano E; Bartolomeazzi R; Conte L
Title Detection of Hazelnut Oil in Virgin Olive Oil by Assessment of Free Sterols and Triacylglycerols.
Journal Journal of the American Oil Chemists Society, 84, 1534-1541
Abstract Free sterols were evaluated as factors for discriminating between genuine virgin olive oil and hazelnut-mixed virgin olive oil. Numeric analyses of the results amplified the differences between groups. The application of this method to virgin olive oil samples and their mixtures with 10% hazelnut oil distinguished between genuine and no genuine virgin olive oil with statistical certainty. Triacylglycerol analysis was tested for the same purpose by using parameter DECN42; but although it possessed a discriminating capacity, it alone could not distinguish the aforementioned groups with sufficient certainty. Free D7-sterols data were combined with DECN42 data into a single discriminating function to improve differentiation and bring more ruggedness, and for detection of low amounts (10%) of hazelnut oil in virgin olive oil. In fact, the values obtained by addition of D7-sterol data and DECN42 data showed a higher discriminating capacity than single parameters. In a single operation the method produced all the oil fractions necessary for analysis of free sterols and triacylglycerols with ECN42. Solid-phase extraction was applied in substitution of traditional chromatography on a silica column.
Authors Mavroustakos T; Zervou M; Bonas G; Kolocouris A; Petrakis P
Title A novel Analytical Method to Detect Adulteration of Virgin Olive Oil by Other oils
Journal Journal of Agricultural and Food Chemistry, 77, 405-411
Keywords Adulterations; high-resolution,13C NMR spectrocopy, Virgin olive oil;
Abstract The present study focuses on the olefinic region of the 13C nuclear magnetic resonance (13 C NMR) spectrum of virgin olive oil which shows 12 peaks resonating between 127.5 and 130ppm. These peaks are assigned to the most abundant unsaturated fatty acid moieties of the olive oil; oleic and linoleic acids, which are present in a and b positions of the glycerol backbone. With the use of an internal reference pyrazine, the 12 peaks were integrated and their areas were expressed in mmol/g of virgin olive oil. The intensities of the 12 observed peaks were affected when an authentic virgin olive oil was mixed with a seed oil. This observation was used to develop a Semiquantitative method to detect adulteration of virgin olive oil by other oils based on 13C NMR spectroscopy.
Authors Fauhl C; Reniero F; Guillou C
Title 1H NMR as a tool for the analysis of mixtures of virgin olive oil with oils of different botanical
Journal Magnetic Resonance in Chemistry, 38, 436-443
Keywords 1H NMR; authentication; multivariate statistics; olive oil;
Abstract 1H NMR spectroscopy provides a possible alternative to conventional chromatographic methods for determining the composition of oils. In this study; various oils from olive, hazelnut and sunflower were analyzed by 1H NMR spectroscopy. Experimental conditions were chosen in order to have a short experimental time. It was demonstrated that multivariate statiscal methods, in particular discriminant analysis, applied to selected predominant peaks in the 1H NMR spectra of oils resulted in a good separation between these three oils of different botanical origin and permitted the detection of their mixtures.
Authors R. Aparicio; R. Aparicio-Ruiz
Title Authentication of vegetable oils by chromatographic techniques
Journal Journal of Chromatography A, 881, 94-104
Keywords Reviews; Vegetable oils; Fatty acids; Triglycerides; Waxes; Sterols; Hydrocarbons; Alcohols; Vitamins
Abstract Food authentication has been evolving continually to situations that were basically governed by a global market trend. Analytical techniques have been developed or modified to give plausible solutions to the devious adulterations at each moment. Classical tests have largely been replaced with newer techniques procedures; most of which are based on gas chromatography, with some being based on high-performance liquid chromatography.
Determination of trans-fatty acid and sterolic composition, together with sterol-dehydration products, have been used most frequently used to detect contamination and adulteration. Sophisticated new adulterations, e.g., olive oil with hazelnut oil, represent a new challenge for the next millennium, although suggestive proposals for detecting these kinds of adulterations are emerging with the contribution of databases and mathematical algorithms. All this and more was reviewed with 152 references.
Authors Pardo M; Sbervbeglieri G; Gardini S; Dalcanale E
Title A hierarchical classification scheme for an Electronic Nose
Journal Sensors and Actuators B, 69, 359-365
Keywords ANN; classification; Electronic nose; Hierarchical; Pattern recognition; SIMCA;
Abstract A procedure for the classification of data from an Electronic Nose (EN) is proposed; which is beneficial in the case in which the of classes is big and/or the classes are not nicely clustered (for instance, as seen in a PCA score plot). The procedure consists of separating the original classification problem in successive, less demanding sub-classification tasks. The advantages, which are due to the greater flexibility, include the following: smaller processing times, enhanced performances and better interpretation of the results. Each classification step uses PCA and Multilayer Perceptrons (MLP) in cascade and, for comparison, Simca. The method has been tested on a data set formed by 242 measurements of 14 olive oil types performed with a commercial EN that was equipped with 12 MOS sensors.
Authors Guadarrama A; Rodríguez-Méndez ML; de Saja JA; Ríos JL; Olías JM
Title Array of sensors based on conducting polymers for the quality control of the aroma of the virgin olive oil
Journal Sensors and Actuators B, 69, 276-282
Keywords 3-Methyl thiophene; Aniline; Conducting polymers; Electronic nose; olive oil; Pyrrol; Sensors;
Abstract In this paper; a sensor array based on thin films of conducting polymers aiming to discriminate among different virgin olive oils is described. The array has been constructed using eight polymeric sensors. They were deposited electrochemically by using different electrodeposition conditions, different monomers (3-methylthiophene, pyrrole and aniline) and doping agents. Olive oil samples with well-defined organoleptic characteristics have been selected by a panel of experts. They included virgin olive oils of different qualities (extra virgin, virgin and lampante) as well as a refined olive oil. Four types of olive oil samples with well-defined 'off dours', that is with unpleasant aromatic notes, named musty, rancid, fusty and muddy, have also been included in the study. The sensors are stable and show good reproducibility and reversibility when exposed to the headspace of the virgin olive oils. The array of sensors combined with a Principal Component Analysis (PCA) allows the discrimination of different types of olive oils.
Authors Guillén MD; Ruiz A
Title High resolution 1H nuclear magnetic resonance in the study of edible oils and fats.
Journal Food Science and Technology, 1-11
Abstract In this paper a review of the applications of high resolution 1H NMR to the study of edible oils and fats is reported. Aspects such as sample preparation and acquisition parameters are treated. The assignment of the 1H NMR signals of the major and minor components of unoxidized and of thermally stressed edible oil and fats is given. The usefulness of this technique in the determination of degree of unsaturation and of the proportion of the different acyl groups; is examined. In addition, the capability of this technique to assess the quality and genuineness of olive oil and to detect adulterations is discussed. Finally, its contribution in the study of the oxidation of edible oils and fats and its effectiveness to determine not only primary but also secondary oxidation products, and also oxidative stability is shown.
Authors V. Baeten; P. Dardenne, R. Aparicio
Title Interpretation of fourier transform Raman Spectra of the unsaponifiable matter in a selection of Edible oils
Journal American Chemical Society, 49, 5098-5107
Abstract The unsaponifiable matter of edible oils is a source of information for their characterization and authentication. FT-Raman spectroscopy has been applied with success to the determination of the spectra of unsaponifiable matter of varietal olive oils as well as other refined and crude edible oils. The spectra of the major unsaponifiable series of compounds (squalene; sterolic and terpenic alcoholic fractions), together with β-carotene and lutein, have been used to explain the most prominent bands found in the spectra of the unsaponifiable matter of 15 edible oil samples (including 10 olive oils, 2 hazelnut oils and samples of corn, sunflower and soybean oils). The order of the scattering intensities of the varietal olive oils agrees with the results obtained by chromatography. An unsupervised multivariate statistical analysis of selected bands points out differences between olive oils and other seed oils, and also among varietal virgin olive oils.
Authors Penza M; Cassano G; Tortorella F; Zaccaria G
Title Classification of food, beverages and perfumes by WO3 thin-film sensors array and pattern recognition techniques
Journal Sensors and Actuators B, 73, 76-87
Keywords Chemical sensors array; cluster analysis; food analysis; Perfumes quality control; Principal components analysis; Sensitive WO3 thin films;
Abstract We have designed and fabricated a sensors array using WO3 thin films operating at the temperature of 180ºC for food and perfume analysis purposes. The sensing surface of the rf sputtered WO3 thin films has been differently activated by evaporated Pd; Au, Bi, Sb catalysts. Pattern recognition (OARC) techniques as principal components analysis (PCA) and cluster analysis (CA) have been used in order to classify and identify different classes of flavors samples such as olive oils and seed oils, fruit juices, tomato sauces, perfumes. Good separation among flavors samples belonging to homogeneous and comparable classes has been obtained by PARC methods. The headspace sampling has been referenced off-line by qualitative chromatograms of the volatile compounds constituent the odour under test. The preliminary results show the feasibility of the electronic nose system to discriminate various flavors for food analysis and perfumes quality control.
Authors Campanella L; Sammartino MP; Tomassetti M; Zannella S
Title Hydroperoxide determination by a catalasse OPEE: application to the study of extra virgin olive oil rancidification process
Journal Sensors and Actuators B, 76, 158-165
Keywords Catalase OPEE; Determination; Hydroperoxides; Olive oil rancidification;
Abstract A new application to authentic matrices of a catalase organic phase enzyme electrode (OPEE) recently developed by the present authors is described in this communication. This biosensor was obtained by coupling an amperometric gas diffusion electrode for the oxygen; made of teflon, and the catalase enzyme immobilized in kappa-carrageenan gel. The response of the catalase biosensor to cumene hydroperoxide and to terbutylhydroperoxide, working directly in n-decane or toluene, was studied. The hydroperoxide content of the extra virgin olive oil was monitored during an artificial rancidification process. One interesting result obtained is the qualitative correlation observed between the above trend of hydroperoxide content pool and that of the peroxide ; moreover, a qualitative inverse correlation trend was found between both the last two indicators and the content of polyphenols in the olive oil which are known to be the most important natural antioxidant agents contained in olive oil.
Authors Gutiérrez N; Rodríguez-Méndez ML; de Saja JA
Title Array of sensors based on lanthanide bisphtahlocyanine Langmuir-Blodgett films for the detection of olive oil aroma
Journal Sensors and Actuators B, 77, 437-442
Keywords Bisphtahlocyanine; Electronic nose; Langmuir-Blodgett films; olive oil; Phthalocyanines; sensor array; Sensors;
Abstract In this paper a sensor array based on Langmuir-Blodgett (LB) films of lanthanide bisphtahlocyanine (LnPc2) aiming to discriminate among diverse virgin oils has been designed. For this purpose; sensors based on bisphtahlocyanines including unsubstituted bisphtahlocyanines with different central metal atom (PrPc2 and LuPc2) and a octaterbutyl substituted bisphtahlocyanine (PrPtc2) have been prepared. The interaction of the sensors with the headspace of olive oil samples has been studied by registering the changes in the conductivity produced in the LB films. The influence in the response of parameters such as the of monolayers or the proportion of arachidic acid used in the preparation of the LB films has been analyzed. Studies on the stability and reproducibility of the LB film-based sensors have been carried out. Using the previous results, the sensors with the best performance characteristics have been selected, and an array of five sensors has been constructed. The array has been exposed to four types of Spanish olive oils with different organoleptic properties and qualities. The principal component analysis of the obtained signals has allowed the discrimination of the different types of olive oils.
Authors Baeten V; Dardenne P; Aparicio R
Title Interpretation of Fourier Transform Raman Spectra of the Unsaponifiable Matter in a Selection of Edible Oils.
Journal Journal of Agricultural and Food Chemistry 49, 5098-5107
Keywords carotenoids; hazelnut oil; olive oil; raman spectroscopy; seed oils; squalene; unsaponifiable
Abstract The unsaponifiable matter of edible oils is a source of information for their characterization and authentication. FT-Raman spectroscopy has been applied with success to the determination of the spectra of the unsaponifiable matter of varietal olive oils as well as other refined and crude edible oils. The spectra of the major unsaponifiable series of compounds (squalene; sterolic, and terpenic alcoholic fractions), together with b-carotene and lutein, have been used to explain the most prominent bands found in the spectra of the unsaponifiable matter of 15 edible oil samples. The order of the scattering intensities of the varietal olive oils agrees with the results obtained by cromatography. An unsupervised multivariate statistical analysis of selected bands points out differences between olive oils and the other seed oils and also among varietal virgin olive oils.
Authors Gordon MH; Cowell C; Kirsch N
Title Detection of Pressed Hazelnut Oil in Admixtures with Virgin olive Oil by Analysis of Polar
Journal Journal of the American Oil Chemists Society, 78, 621-624
Keywords Adulteration; hazelnut oil; olive oil; phenolics;
Abstract Analysis of the polar fraction from virgin olive oil and pressed hazelnut oil by high-performance liquid chromatography showed marked differences in the chromatograms of the polar components in the two oils. Six commercial samples of pressed hazelnut oil and 12 samples of virgin olive oil (or blended olive oil including virgin olive oil) were analyzed. The phonemic content on the pressed hazelnut oil samples was 161 6 mg.kg-1. Inspection of the chromatograms showed that the pressed hazelnut oil extracts contained a component that eluted in a region of the chromatogram that was clear in the olive oil samples; and consequently this component could be used to detect adulteration of virgin olive oil by pressed hazelnut oil. The component had a relative retention time of 0.9 relative to 4-hydroxybenzoic acid added to the oil as an internal standard. The ultraviolet spectrum of the component showed a maximum at 293.8 N.M., but the component could not be identified. Analysis of blends of oils showed that adulteration of virgin olive oil by commercial pressed hazelnut oil could be detected at a level of about 2,5%.
Authors Ricci C; Allai M; Ribechini L; Dalcanale E; Caglioti L
Title Valutazione della qualita dell 'ólio extra vergine di oliva mediante naso elettronico a sensori MOS
Journal Rivista Italiana delle Sostanze Grasse, 48, 85-92
Abstract Electronic noses are becoming a valuable tool for the organoleptic evaluation of food freshness; seasoning, geographical origin and shelf--life. This article reports a series of experiments aimed to highlight potentials and limits of MOS electronic noses for detecting defects present in extra virgin olive oil. The instrument is also able to discriminate olive oils obtained from the same fruits using respectively milling of stoned olives and traditional milling.
Authors Zamora R; Alba V; Hidalgo FJ
Title Use of high-resolution 13C Nuclear Magnetic Resonance Spectroscopy for the screening of Virgin Olive Oils
Journal Journal of the American Oil Chemists Society, 78, 89-94
Keywords Adulteration; high-resolution 13C NMR; oil characterization; Pattern recognition; stepwise discriminant analysis; vegetable oils; virgin olive oil;
Abstract 13C Nuclear magnetic resonance (NMR) spectra of 104 oil samples were obtained and analyzed in order to study the use of this technique for routine screening of virgin olive oils. The oils studied included the following. virgin olive oils from different cultivars and regions of Europe and north Africa; and refined olive, 'lampante' olive, refined olive pomace, high-oleic sunflower, hazelnut, sunflower, corn, soybean, rapeseed, grapeseed, and peanuts oils, as well as mixtures of virgin olive oils from different geographical origins and mixtures of 5-50% hazelnut oil in virgin olive oil. The analysis of the spectra allowed us to distinguish among virgin olive oils, oils with a high content of oleic acid, and oils with a high content of linoleic acid, by using stepwise discriminant analysis. This parametric method gave 97.1% correct validated classifications for the oils. In addition, it classified correctly all the hazelnut oil samples and the mixtures of hazelnut oil in virgin olive oil assayed. All of these results suggested that 13C NMR may be used satisfactorily for discriminating some specific groups of oils, but to obtain 100% correct classifications for the different oils and mixtures, more information than that obtained from the direct spectra of the oils is needed.
Authors Moreno Cordero B; Cerrato Oliveros MC; Pérez Pavón JL; García Pinto C; Fernández Laespada ME; Forina M
Title Electronic nose based on metal oxide semiconductor sensors as a fast alternative for the detection of adulteration of virgin olive oils
Journal Analytica Chimica Acta, 459, 219-228
Keywords Adulteration; electronic olfactometry; metal oxide semiconductor gas sensors; supervised pattern recognition techniques; Virgin olive oils;
Abstract An 'Electronic nose' has been used for the detection of adulterations of virgin olive oil. The system; comprising 12 metal oxide semiconductor sensors, was used to generate a pattern recognition treatments, feature selection techniques were employed to choose a set of optimally discriminant variables. Linear discriminant analysis (LDA), quadratic discriminant analysis (QDA) and artificial neural networks (ANN) were applied. Excellent results were obtained in the differentiation of adulterated and non-adulterated olive oils and it was even possible to identify the type of oil used in the adulteration. Promising results were also obtained as regards quantification of the percentages of adulteration.
Authors Saitta M; Lo Curto S; Salvo F; Di Bella G; Dugo G
Title Gas chromatographic - tandem mass spectrometric identification of phenolic compounds in Sicilian olive oils.
Journal Analytica Chimica Acta, 466, 335-344
Keywords gas chromatography; mass spectrometry; MS/MS; olive oils; phenols;
Abstract Phenolic compounds in Sicilian olive oils were analyzed by GC--MS and GC --MS/MS after extraction with methanol: water 80:20 and derivatization with bis (trimethylsilyl) trifluoracetamide and trimethylchlorosilane (BSTFA: TMCS 99:1). Numerous compounds were detected and 23 were identified. Tyrosol; hydroxytyrosol and the decarbomethoxy ligstroside and oleuropein aglycons in the dialdehydic forms were the most abundant compounds. 4--(Acetoxyethyl)-1-hydroxybenzene, 3,4-dihydroxyphenylacetaldehyde, syringaldehyde and the cis form of ferulic acid were identified: these compounds were not found in olive oils before. The presence of the dialdehydic form of elenolic acid (without carbomethoxy group) linked to 3-methoxy-4-hydroxyphenylethanol was hypothesized. There were quantitative differences in oils from the varieties Nocellara del Belice, Santagatese and Cerasuola; these differences could depend on the olive varieties and ripenes.
Authors Baur FJ
Title Analytical Methods for Oils and Fats
Journal Journal of the American Oil Chemists Society, 281-289
Authors Cercaci L; Rodriguez-Estrada MTLG
Title Solid-phase extraction-thin-layer chromatography-gaschromatographic method for the detection of hazelnut oil in olive oils by determination of esterified sterols
Journal Journal of Chromatography A, 985, 211-220
Keywords food analysis; olive oil; sterols;
Abstract The sterol composition of extra virgin olive oil is very characteristic and; thus, has become a helpful tool to detect adulterations with other vegetables oils. Special attention has been addressed to the separate determination of the free and esterified sterol fractions, since both have different compositions and can thus provide more precise information about the actual origin of the olive oil. In the case of admixtures with small amounts of hazelnut oil, this approach can be extremely useful, because the similarity between the fatty acid compositions of both oils hampers the detection of the fraud. A hyphenated chromatographic method was developed for a sensitive and precise determination of esterified sterols in olive oils. The oil was subjected to silica TLC. The sterol band was then injected into an SPB-5 (30 m x 0,25 mm I:D., 0.25 um film thickness) and the ratio [ % campesterol x (% 7-stigmastenol)2]/(% 7- avenasterol) was calculated. The method was tested on extra virgin olive oil; good sterol recoveries and repeatability were obtained. The results were compared with another method, which has a different sample preparation sequence (silica chromatography, hot saponification and silica TCL). Similar results were achieved with both methods; however, the SPE-method was applied to an admixture with 10% of hazelnut oil and to screening of 11 oils (husk oil virgin and refined olive oils) from different Mediterranean countries.
Authors Vlahov G; Shaw A D; Kell DB
Title Use of 13C Nuclear Magnetic Resonance Distortionless Enhancement by Polarization Transfer Pulse Sequence and Multivariate Analysis to Discriminate Olive oil cultivars
Journal Journal of the American Oil Chemists Society, 76, 1223-1231
Keywords 13C-NMR; multivariated analysis; olive oil;
Abstract Distortionless enhancement by polarization transfer (DEPT) pulse sequence was used to set up a quantitative high-resolution 13C nuclear magnetic resonance (NMR) method to discriminate olive oils by cultivar and geographical origin. DEPT pulse sequence enhances the intensity of NMR signals from nuclei of low magnetogyric ratio. The nuclear spin polarization in transferred from spin with lsrge Boltzmann population differences (usually protons) to nuclear species characterized by low Boltzmann factors; e.g., 13C. The signal enhancement of 13C spectra ensures the accuracy of resonance intensities of different spectra must be compared. The resonances of triglyceride acyl chains Cn:0' C18:1' C18:2' and C18:3' were also assigned. Multivariate analysis was carried out on the 35 carbon signals obtained. By using variable reduction techniques, coupled with standard statistical methods- it was largely possible separate the samples according to their variety and region of origin. With one problem variety removed, 100% prediction of the three remaining varieties was achieved. Similarly, by using the three regions with greatest representation in the data, all but one of a test set of 34 samples were correctly predicted. Thus, the composition of olive oils from different cultivars and of different geographical origin were compared and successfully studied by multivariate analysis. These considerations in conjunction with the structural elucidations of triglyceride molecules demonstrated that 13C NMR is among the most powerful techniques yet described for analysis of olive oils.
Authors Serani A; Piacenti D
Title Sistema analitico per l'identificazione di oli deodorati in oli vergini di oliva Nota1- Analisi dei pigmenti clorofilliani in oli vergini di oliva
Journal Rivista Italiana delle Sostanze Grasse, 78, 459-463
Keywords chlorophyll; pheophytin; pigments; Pyropheophytin;
Abstract Il colore verde degli oli extra vergine di oliva è dovuto essenzialmente alla presenza di pigmenti clorofilliani:clorofilla-A; che si idrolizza dopo poco tempo dall'estrazione dell'olio dalle olive,feofitine di tipo A e in piccola parte da pirofeofitina-A, ottenuta per decomposizione naturale della feofitina -A durante l'invecchiamento e lo stoccagio dell'olio. Effttuando dei trattamenti termici, sugli oli vergini di oliva, viene aumentata la velocitá di decomposizione delle feofitine di tipo A generando un contenuto di pirofeofitina-A maggiore di quanto permesso dalla sua decomposizione naturale Dall'analisi di vari oli vergini dioliva, di diversa origine e differeni epoche di raccolta, è stato possibile stabilire una relazione lineare tra il contenuto reale di feofitine di tipo A e pirofeofitina- A presenti negli oli vergini di oliva. La differenza tra il contenuto reale di pirofeofitina-A e quello calcolato dalla quantitá di feofitine di tipo A presenti negli oli analizzati, ci ha permesso di trovare un indice, correato annche al rapporto tra questi pigmenti ('cold index'), che evidenzia la presenza di oli trattati termicamente in oli vergini di oliva.
Authors Blanch GP; Caja MMRdCML; Herrraiz M
Title A contribution to the study of the enantiomeric composition of chiral constituent in hazelnut oil used in the detection of adulterated olive oil
Journal Euro Food Res Technol, 210, 139-143
Keywords Adulterated olive oil; Enantiomeric composition; hazelnut oil; On-lie reserve-phase liquid chromatography to gas chromatography; Simultaneous distillation extraction;
Abstract A method is proposed for the determination of adulteration of olive oil with hazelnut oil which is based on the study of the enantiomeric makeup of (E)-5-methylhept-2-en4-one (filbertone). The possibilities of either using a sample preparation technique or performing direct injection of the samples (i.e.; without any kind of sample pretreatment) are considered and both simultaneous distillation extraction followed by gas chromatographic analysis and direct injection in online coupled reverse-phase liquid chromatography to gas chromatography are used. In both cases, a chiral stationary phase is employed in the gas chromatography step and the determination of the enantiomeric composition of filbertone is recommended for an accurate evaluation and quick control for detecting the adulteration of olive oil with hazelnut oil.
Authors García-Gonzalez D; Aparicio R
Title Detection of Vinegary Defect in Virgin Olive Oils by Metal Oxide Sensors
Journal Journal of Agricultural and Food Chemistry, 50, 1809-1814
Keywords Electronic noses; olive oil; regression; vinegary defect;
Abstract An array of metal oxide sensors has been set up for detecting the vinegary defect in virgin olive oil. The optimization process was carried out evaluating the variables affecting the process by three desirability functions. Repeatability studies for 6 months and within day were done to evaluate the sensor responses and remove those with high relative standard deviation. The sensor responses were preprocessed applying five weight functions previously to build a regression model. Samples of Spanish Arbequina and Picual virgin olive oil varieties spiked with different amounts of acetic acid (15-200 mg/L) were used as a training set for the regression model. The test set was composed of samples of Italian Coratina virgin olive oil spiked with the vinegary standard at five percentages (10; 25,40,50, and 75) A fine-adjusted regression coefficient (Radj2 = 0.98) was computed with the test set.
Authors Reiners J; Grosch W
Title Concentration of 4-methoxy-2methyl-2buthanthiol in Spanish virgin olive oils
Journal Food Chemistry, 64, 45-47
Keywords Virgin olive oils;
Abstract The sensitivity of stable isotope dilution assay for 4-methoxy-2methyl-2-butanethiol (MMB) causing the blackcurrant-like odour in olive oils was improved. After spiking the oil sample with labeled MMB; the thiols were separated from the volatile fraction with an immobilized reagent for thiols. MMB and its standard were purified by multi-dimensional gas chromatography of the thiol fraction and determined by mass spectrometry. The new procedure was applied to three Spanish oils differing in the intensity of their blackcurrant-like odour note. The concentrations of MMB lay between 0.4 mg kg -1 and 4.3 mg kg -1.
Authors García-Gonzalez D; Aparicio R
Title Detection of defective virgin olive oils by metal-oxide sensors
Journal European Food Research and Technology, 215, 118-123
Keywords chemometrics; Electronic nose; Fusty; olive oil; Rancidity; vinegary;
Abstract An array of metal-oxide sensors was set up for detecting the vinegary; rancid and fusty defects in virgin olive oils. Spanish Farga and Picual olive varieties were spiked with these defective sensory attributes. The optimization process was carried out taking into account the variables affecting the process that were evaluated by three desirability functions. Repeatability studies for six months and within-day were done to evaluate the sensor responses. The responses were preprocessed applying four selected zones (windowed time slicing) of the sensor responses. Assessors carried out the sensory evaluation while the quantification of volatiles was made by gas chromatography (dynamic headspace and thermal desorption). Canonical correlation was applied to study sensor responses versus sensory evaluations and volatile concentrations. Total phenols and fatty acids were quantified for a better understanding of rancid process induced by ultraviolet beam. Fusty attribute was explained by sensor responses (Multiple-R=0.98) using multiple linear regression on the principal components. Samples were completely distinguished according to their defective attributes by applying stepwise linear discriminant analysis on first four factors of PCA.
Authors Reiners J; Grosch W
Title Odorants of Virgin Olive Oils with Different flavor profiles
Journal Journal of Agricultural and Food Chemistry, 46, 2754-2763
Keywords aroma extract dilution analysis; flavor differences; flavor imitation; flavor profile analysis, isotope dilution assay, sensory study; Virgin olive oil;
Abstract The potent odorants of virgin olive oils from Italy (I); Spain (S), and Morocco (M) were screened by aroma extract dilution analyses and gas chromatography olfactometry of headspace samples. After quantification, odor activity values (OAVs) were calculated by dividing the concentrations of the odorants in the oil samples by their nasally and retronasally determined odor threshold values in sunflower oil. On the basis of the nasal thresholds, the following compounds showed high OAVs in the oils given in parentheses: acetaldehyde (I,S,M), acetic acid (I,S), propanal (I), 1-penten-3-one (I), (E,Z)-2,4-decadienal (I,M), trans-4,5-epoxy-(E)-2-decenal (I,S,M), (Z9-3-hexenal (I,M), (E)-2hexenal (I), (Z9-3hexenyl acetate (I), 4-methoxy-2-butanethiol (S), ethyl 2-and 3-methylbutyrate (S,M), 2-and 3-methylbutanal (S), ethyl cyclohexylcarboxylate (M), and ethyl isobutyrate (M). Higher OAVs were additionally found for hexanal (I) and (Z)-2-nonenal (I,M) when retronasally odor thresholds were used as the basis. The potent odorants were dissolved in a refined plant oil in the concentrations found in the three olive oil samples. The flavor profiles of the models obtained were very close to those of the real samples, indicating that the different notes in the flavor profiles of these oils could those of the real samples, indicating that the different notes in the flavor profiles of these oils could be reproduced, e.g., green, fruity, black currant like. Models missing one or several compounds with the same odor quality gave an insight into the importance of the odorants contributing to the flavor profiles of the oil samples.
Authors Caja MM; Ruiz del Castillo ML; Herraiz M; Blanch GP
Title Study of the Enantiomeric Composition of Chiral Constituents in Edible Oils by simultaneous Distillation-Extraction. Detection of Adulterated Olive Oils
Journal Journal of the American Oil Chemists Society, 76, 1027-1030
Keywords Adulteration; enantiomeric composition, filbertone, hazelnut oil, olive oil,;
Abstract A method is proposed for detecting adulterations of olive oil with hazelnut oil at percentages as low as 5%. The method is based on the identification of R-and-S-enantiomers of E-5-methylhept-2-en-4-one (filbertone) and involves the use of simultaneous distillation-solvent extraction in the sample preparation step and subsequent gas chromatographic analysis with a chiral stationary phase. relative standard deviation values obtained from three replicates of adulterated mixtures of olive oil and hazelnut oil (95:5) were less than 9% for both r-and S-filbertone.
Authors Busconi M; Foroni C; Corradi M; Cattapan F; Fogher C
Title DNA extraction from olive and its use in the identification of the production cultivar
Journal Food Chemistry, 83, 127-134
Keywords AFLP; Cultivar identification; fingerprinting; Olive oil DNA; RAPD; SCAR;
Abstract DNA Recovery from food samples might great importance when the raw material used in the production process has to be traced. We were interested in verifying the presence of nucleic acids in extra virgin olive oil in order to determine the cultivar of origin of the olives used for the production. A reliable DNA extraction method for extra virgin olive oil has been defined; as far as both quantity and quality are concerned, and the possibility of using this DNA for fingerprinting the original cultivar has been demonstrated. DNA extraction was tested on four monovariety oils, plus four commercial extra virgin olive oils. The DNA in the extracted solution was of chloroplast and nuclear origin since we were able to amplify cloned cultivar RAPD and AFLP fragments homologous to nuclear DNA of other species. It has also been shown that DNA purified from oil can be used for AFLP analysis and that the profile of the DNA purified from a monovariety oil corresponds to profile of the DNA purified from the leaves of the same cultivar.
Authors Kiritsakis AK
Title Química del aroma del aceite de oliva
Journal Olivae, 45, 28-33
Keywords Aceite de oliva;
Abstract El delicado aroma del aceite de oliva tiene su origen en un gran número de compuestos: hidrocarburos alifáticos aromáticos; alcoholes alifáticos y triterpernicos, aldehídos, cetonas, ésteres, éteres derivados furanos y tiofenos. Los principales compuestos aromáticos del aceite de oliva son el hexanal, el trans-2-exanal y 1-hexanol. Los cultivares del olivo, las condiciones climáticas, edáficas y culturales, influyen en la formación de estos compuestos y, por tanto, en la química del aroma del aceite de oliva. Los aceites de oliva son susceptibles de adquirir olores causados por la hidrólisis de los glicéridos o por la oxidación de los ácidos grasos insaturados. Durante la oxidación del aceite de oliva se forman diversos compuestos aromáticos como el 2-pentanal y el 2-heptenal que son los principales causantes del olor del aceite de oliva oxidado.
Authors Mavromoustakos T; Zervou M; Theodoropulo E; Panagiotopulos D
Title 13C NMR Analysis of the triglycerol Composition of Greek Virgin Olive Oils
Journal Magnetic Resonance in Chemistry, S3-S7
Keywords Virgin olive oil; gas chromatography;
Authors Cerrato Oliveros MC; Pérez Pavón JL; García Pinto C; Fernández Laespalda ME; Moreno Cordero B; Forina M
Title Electronic nose based on metal oxide semiconductor sensors as a fast alternative for the detection of adulteration of virgin olive oils
Journal Analytica Chimica Acta, 459, 219-228
Keywords electronic olfactometry; Metal oxide semiconductor gas sensors; Supervised pattern recognition techniques; Virgin olive oils;
Abstract An 'electronic nose' has been used for the detection of adulterations of virgin olive oil. The system; comprising 12 metal oxide semiconductor sensors, was used to generate a pattern of the volatile compounds present in the samples. Prior to different supervised pattern recognition treatments, feature selection techniques were employed to choose a set of optimally discriminant variables. Linear discriminant analysis (LDA), quadratic discriminant analysis (QDA) and artificial neural networks (ANN) were applied. Excellent results were obtained in the differentiation of adulterated and non-adulterated olive oils and it was even possible to identify the type of oil used in the adulteration. Promising results were also obtained as regards quantification of the percentages of adulteration.
Authors Biswas S; Heindselmen L; Wohltejen H; Staff C
Title Differentiation of vegetable oils and determination of sunflower oil oxidation using a surface acoustic wave sensing device
Journal Food Control, 15, 19-26
Keywords SPME-GC/MS; SSD; sunflower oil;
Abstract A small portable electronic sensing device; utilizing the principle of surface acoustic wave (SAW), was used to differentiate between olive and sunflower oils of various brands. The oils were oxidized to determine if the sensing device could distinguish between fresh an oxidized oils. Good results were obtained, when adjusted total peak signal magnitudes and sensor frequencies were plotted against oxidation time. The R2 value of the sunflower oils was better than that of the olive oils. Hence, they were considered for analysis by headspace solid phase microextraccion-gas chromatography/mass spectrometry (SPME-GC/MS) for comparison of results between the two methods (SAW sensing device (SSD) and SPME-GC/MS). SPME-GC/MS showed the presence of a of compounds in the oils. However, acetic acid showed a consistent increase in terms of area count as compared to other compounds of the oils: Hence it was considered for a plot of responses from both methods were calculated. This led us to conclude that SSD could prove to be a valuable tool in quality control measurements industry.
Authors Del Río JA; Báidez AG; Botía JM; Ortuño A
Title Enhancement of phenolic compounds in olive plants (Olea europea L.) and their influence on resistance against Phytophthora sp.
Journal Food Chemistry, 83, 75-78
Keywords Antifungal agents; Brotomax; Catechin; tyrosol;
Abstract The total phenol levels in different olive organs and tissues are studied. The PLC-MS studies point to the presence of oleur-opein; cathechin and tyrosol as some of the main phenolic compounds in these extracts. The effect of Brotomax treatment of phenolic compound leves in the plant and possible role of these compounds as antifungal agents against Phytophthora sp. are also studied. An increase in the total phenol content of leaves and stems was observed 120 days after treatment with 0.3% Brotomax. The cortex was the stem tissue which showed the greatest accumulation of these secondary compounds. An in vitro study of the inhibitory effect of these compounds on fugal growth revealed that tyrosol was the most active agent, followed by catechin and oleuropein, their fungitoxic effect being greater when they acted synergically.
Authors Janssen H; Boers W; Steenbergen H; Roos H; Flöter E
Title Comprehensive Two- dimensional liquid chromatography X gas chromatography: evaluation of the applicability for the analysis of edible oils and fats
Journal Journal of Chromatography A, 1000, 385-400
Keywords Comprehensive chromatography; fats; Liquid chromatographyxgas chromatography; comprehensive two-dimensional; oils; Sterol esters; Triglycerides; wax esters;
Abstract Edible fats and oils are complex mixtures containing a wide range of (classes of) compounds. The most important group of compounds are the triglycerides (triacylglycerides; TAGs). Because of the large of possible fatty acid combinations, an enormous of TAGs is possible fatty acid combinations, an enormous of TAGs is possible. In the present feasibility study, the applicability of different modes of comprehensive two-dimensional LCXGC for detailed oil and fat analysis is evaluated. Comprehensive LCXGC was found to be an extremely powerful analytical method for the analysis of complex TAG samples. Using the new comprehensive set-ups, TAGs can be separated according to two independent parameters: carbon vs. of double bonds. The information content of comprehensive separations agreement with data obtained from standard analytical methods. The quantitative results of the separations show a good agreement with data obtained from standard analytical methods. The comprehensive methods studied can also be used for fingerprinting of oil samples, as well as for the analysis of target compounds or compound groups. Highly detailed separations of olive oil samples were obtained. Zooming in on one region of the chromatogram allowed reliable analysis of was esters without interferences of sterol esters.
Authors Morales MT; Luna G
Title Sensory and chemical evaluation of winey-vinegary defect in virgin olive oils
Journal Euro Food Res Technol, 211, 222-228
Keywords flavour; Sensory defects; Virgin olive oil; volatiles; Winey-vinegary;
Abstract Winey-vinegary sensory defect was evaluated in virgin olive oil samples from a sensory and chemical point of view. Qualitative and quantitative differences were found in the profile of volatiles of extra-virgin olive oil samples without sensory defects and samples with high intensities of winey-vinegary sensory attribute. Several volatile compounds were found to be correlated to winey-vinegary sensory attribute. Several volatile compounds were found to be correlation coefficients of 0:98 and 0.94 respectively. A syntestic sample was obtained with the sensory characteristics of the winey defect. Samples with low values of winey sensory defect were also studied and the evaluation of the presence of the defect using the content of four volatile compounds only was demonstrated.
Authors Aparicio R; García-González DL
Title Classification of Different Quality Virgin Olive Oils by Metal-Oxide Sensors
Journal Eurofood Research Technology, 218, 484-487
Keywords Electronic nose; Chemometrics, metal-oxide sensors, olive oil, sensory quality;
Abstract The european Union classifies virgin olive oils into four categories; extra virgin, virgin, ordinary and lampante, the latter being the only that cannot be consumed before a refining process. A mathematical model based on two metal-oxide sensors has been designed and checked for distinguishing on-line lampante oils inside the production systems. The model was trained with 114 samples and successfully checked with two external test of 13 and 42 samples representing 29 varietal olive oils from 8 producer countries.
Authors V. Baeten; J.A. Fernandez Pierna, P. Dardenne, M. Meurens, D.L. García-Gonzalez, R. Aparicio
Title Detection of the Presence of Hazelnut Oil in Olive Oil by FT-Raman and FT-MIR Spectroscopy
Journal Journal of agricultural and food chemistry, 53, 6201-6206
Keywords Olive oil; hazelnut oil; FT-Raman; FT-MIR; chemometrics
Abstract The detection of the presence of refined hazelnut oil in refined olive oil at low percentages is still a challenge with the current official standards. FT-Raman and FT-MIR spectroscopies have been used to determine the level of detection of the presence of hazelnut oil in olive oil. Spectroscopic analysis has been made not only with the entire oil but also with its unsaponifiable matter. Univariate and multivariate statistical models have been designed with this objective. This study shows that a complete discrimination between olive and hazelnut oils is possible and that adulteration can be detected if the presence of hazelnut oil in olive oil is >8% if the blends are of Turkish olive and hazelnut oils. The limit of detection is higher when the blends are of edible oils from diverse geographical origins.
Back to "Divisions"
Back to Start Page