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Herchi W.,Laboratoire Of Biochimie Des Lipides | Arraez-Roman D.,University of Granada | Trabelsi H.,Laboratoire Of Biochimie Des Lipides | Bouali I.,Laboratoire Of Biochimie Des Lipides | And 4 more authors.
Journal of Oleo Science | Year: 2014

Flaxseed has been used for centuries for oil extraction. In recent years it has attracted considerable interest as a result of studies which attribute potential health benefits to its components. Among the compounds that present biological activity, phenolic compounds are of special interest. The dietary lignan secoisolariciresinol diglucoside (SDG) reaches high concentrations in flaxseed. Flaxseed contains also other phenolic compounds, such as phenolic acids. Considering the importance of the phenolic fraction of flaxseed, high performance analytical methods have been developed to characterize its complex phenolic pattern. The understanding of the nature of these compounds is crucial for their possible exploitation in drugs and functional foods. © 2014 by Japan Oil Chemists' Society.


Herchi W.,Laboratoire Of Biochimie Des Lipides | Sawalha S.,University of Granada | Arraez-Roman D.,University of Granada | Boukhchina S.,Laboratoire Of Biochimie Des Lipides | And 3 more authors.
Food Chemistry | Year: 2011

A new method based on high-performance liquid chromatography coupled with electrospray ionisation time-of-flight-mass spectrometry (HPLC-ESI-TOF (MS)) has been used to analyse phenolic compounds in flaxseed oil. Some phenolic compounds such as secoisolariciresnol, ferulic acid and its methyl ester, coumaric acid methyl ester, diphyllin, pinoresinol, matairesinol, p-hydroxybenzoic acid, vanillin and vanillic acid have been detected from flaxseed oil. The quantification of these compounds in three varieties of flaxseed oils was carried out using their commercial standards. The efficiency, rapidity and high resolution of HPLC coupled to the sensitivity, selectivity, mass accuracy and true isotopic pattern from TOF (MS) have revealed an enormous separation potential allowing the determination of a broad series of phenolic and other polar compounds present in flaxseed oil for the first time. © 2010 Elsevier Ltd. All rights reserved.


Herchi W.,Laboratoire Of Biochimie Des Lipides | Arraez-Roman D.,University of Granada | Boukhchina S.,Laboratoire Of Biochimie Des Lipides | Kallel H.,Laboratoire Of Biochimie Des Lipides | And 2 more authors.
African Journal of Biotechnology | Year: 2012

Flaxseed (Linum usitatissimum L.) is a multi-purpose crop and its consumption is beneficial for human health. The nutritional components of flaxseed are oil, protein, lignans, fiber and vitamin. The determination of the minor components is of great importance in establishing the flaxseed oil quality and their genuineness. The qualitative and quantitative determination of its constituents has been carried out by using several analytical techniques most of which are based on gas chromatography and some being based on high-performance liquid chromatography. In the present work, the different methods used for the determination of flaxseed components are revised. © 2012 Academic Journals.


Sakouhi F.,Laboratoire Of Biochimie Des Lipides | Absalon C.,CNRS Institute of Molecular Sciences | Kallel H.,Laboratoire Of Biochimie Des Lipides | Boukhchina S.,Laboratoire Of Biochimie Des Lipides
European Journal of Lipid Science and Technology | Year: 2010

MALDI-TOFMS and HPLC are two analytical methods that were used to characterize triacylglycerols (TAG) of the Meski, Sayali, and Picholine Tunisian olive varieties. The HPLC chromatograms of the oils showed the presence of 15 TAG species, among which triolein (OOO) was the most abundant (21-48%). In the Sayali cultivar, OOO was the predominant TAG species followed by POO and LOO. However, the minor TAG molecules were represented by LnLO and LnLP. MALDI mass spectra produced sodiated ([M + Na]+) and potassiated ([M + K]+) TAG molecules; only the major TAG were potassiated [OOO + K] ([OOO + K]+, [POO + K]+, and [LOO + K]+). In contrast to the HPLC chromatograms, the MALDI mass spectra showed 13 peaks of TAG. The major peak was detected at m/z 907, which corresponds to OOO with an Na+ adduct. The results from both HPLC and MALDI techniques predict the fatty acid composition and their percentages for each olive variety. Practical applications: TAG are the main components in vegetable oils. These biomolecules determine the physical, chemical, and nutritional properties of the oils. The nutritional benefits of TAG are related to DAG (moderate plasma lipid level) and esterified FA, which are intermediate biosynthetic molecules of TAG. TAG analysis is necessary to discriminate between oils of different origin, since some oils have similar FA profiles. Olive products, oils, and table olives, are the main diet sources of TAG in the Mediterranean countries. In this work, chromatographic and spectrometric methods were used for TAG analysis and characterization of Tunisian olive varieties.


Sakouhi F.,Laboratoire Of Biochimie Des Lipides | Boukhchina S.,Laboratoire Of Biochimie Des Lipides | Absalon C.,CNRS Institute of Molecular Sciences | Fouquet E.,CNRS Institute of Molecular Sciences | Kallel H.,Laboratoire Of Biochimie Des Lipides
European Journal of Lipid Science and Technology | Year: 2010

Policosanol is a mixture of bioactive molecules shown to have beneficial effects in treating hypercholesterolemia. Food products enriched in policosanol are currently available in the US market. In the present study, eight policosanol components were identified by GC-MS during the ripening of Meski olives. The quantitative characterization of these compounds was performed using GC-FID. The results showed that the maximum level of total policosanol components (947.20 mg/100 g oil) was reached at the 26th week after the flowering date of Meski olives. Hexacosanol and tetracosanol were the predominant policosanol components at Meski olivematurity. However pentacosanol, heptacosanol and tricosanol were less present in the olives and they accounted for 14% of the total policosanol at complete maturity of the fruit. The total policosanol content of Meski olives was higher than that of beeswax and whole sugar cane, which belong to the sources of dietary supplements containing policosanol. These findings indicate that olive is a potential source of these health-enhancing compounds for functional foods and nutraceutical applications. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Sakouhi F.,Laboratoire Of Biochimie Des Lipides | Herchi W.,Laboratoire Of Biochimie Des Lipides | Sebei K.,Laboratoire Of Biochimie Des Lipides | Absalon C.,CNRS Institute of Molecular Sciences | And 2 more authors.
Scientia Horticulturae | Year: 2011

The objective of the present study was to monitor total lipids, fatty acids and triacylglycerols accumulation during development and ripening of Sayali olive fruit (of Olea europaea L.). Results showed that the accumulation of both major fatty acids and total lipids were slightly influenced by the ripeness stages of olive fruit. Moreover, the weight and the lipid content of the olive seem to be influenced by the climatic conditions of the studied area. The greatest changes in fatty acids content occurred early during the six firsts weeks after the flowering date of the fruit. Also, the results revealed important correlations on the fatty acids accumulation patterns during the olive development and ripening. Moreover, some of triacylglycerol species as OOO (oleyl O), LOO (linoleyl L) and POO (palmityl P) showed notable variations in their percentages during the maturity process. However, LOP, POP and SOO (stearyl S) seem to be invariable during the development of Sayali olive. Oleic acid (C18:1), which has numerous healthy properties, was found at highest level (more than 70% of total fatty acids) at all stages of olive maturity. These results revealed that olive fruit was a potential source of beneficial unsaturated fatty acids which have particular attention from the food industry. © 2011 Elsevier B.V.


Sakouhi F.,Laboratoire Of Biochimie Des Lipides | Herchi W.,Laboratoire Of Biochimie Des Lipides | Sbei K.,Laboratoire Of Biochimie Des Lipides | Absalon C.,CNRS Institute of Molecular Sciences | Boukhchina S.,Laboratoire Of Biochimie Des Lipides
International Journal of Food Science and Technology | Year: 2011

The present investigation was carried out for the analysis of hydrocarbon compounds of Tunisian Meski olives. The hydrocarbon fraction of the oils was found to contain twelve n-alkanes (C 22-C 36) and squalene. Results from the quantitative characterisation of the oils revealed that squalene was the most abundant hydrocarbon compound, at all development stages of Meski olive, accounting for more 92% of total hydrocarbons. Pentacosane (C 25), heptacosane (C 27) and tricosane (C 23) represented the major compounds of n-alkanes. The highest accumulation of n-alkanes and squalene was observed at early stages of olive development [before 21st week after the flowering date (WAFD)]. The greatest decrease of these components occurred between 21st and 26th WAFD of the olives. At complete maturity of the fruit, the level of squalene and total n-alkanes was 126.52 and 9.13mg per 100g oil, respectively. Hence, the content of n-alkanes and squalene was remarkably influenced by the ripeness process of olive. © 2011 The Authors. International Journal of Food Science and Technology © 2011 Institute of Food Science and Technology.


Trabelsi H.,Laboratoire Of Biochimie Des Lipides | Cherif O.A.,Laboratoire Of Biochimie Des Lipides | Sakouhi F.,Laboratoire Of Biochimie Des Lipides | Villeneuve P.,CIRAD - Agricultural Research for Development | And 4 more authors.
Food Chemistry | Year: 2012

This research has determined oil, fatty acid and sterol contents of the Tunisian Pistacia lentiscus (Lentisc) fruits during maturation. Low oil accumulation was observed during the first 35 days after the fruiting (DAF) date (from 1.83% to 2.57%). After that, two phases were distinguished (35th until the 60th and 105th to the 145th DAF), where the rate of oil accumulation increased significantly. At the last stage of maturation, the lentisc fruits had the highest percentage of lipid content, 42.54%. The changing profile of fatty acids during maturation had been marked mainly by an increase in oleic acid content (from 19.49% to 50.72%) paralleling a decrease in linoleic acid content (from 42.5% to 21.75%). At the 15th DAF, the alpha-linolenic acid was found with a maximum of 13.81%. At full maturity, the main fatty acids were oleic acid, followed by palmitic and linoleic acid. Other fatty acids were present in trace proportions, such as palmitoleic, stearic, linolenic, gadoleic and arachidic acid. In all stages of ripening only four sterols were identified and quantified. β-Sitosterol was the major 4-desmethylsterol in samples tested, followed by campesterol. Cholesterol and stigmasterol were detected in trace amounts. During the first stage of ripening, the amount of total sterols was about 5.19/100 g of oil. It decreased to 0.43/100 g in the last stage. Sitosterol and campesterol showed nearly the same profile during the ripening of P. lentiscus fruit which could be linked to the relation between these compounds during their biosynthesis. © 2011 Elsevier Ltd. All rights reserved.


Herchi W.,Laboratoire Of Biochimie Des Lipides | Sakouhi F.,Laboratoire Of Biochimie Des Lipides | Khaled S.,Laboratoire Of Biochimie Des Lipides | Xiong Y.,University of Alberta | And 3 more authors.
Food Chemistry | Year: 2011

A high-performance liquid chromatographic method coupled with mass spectrometry was used to characterise the natural phospholipid (PL) classes and molecular species in flaxseed oils. The PL fraction included phosphatidylethanolamine (PE) (27-40%), phosphatidylinositol (PI) (29-32%), phosphatidylcholine (PC) (7-18%), lysophosphatidylcholine (LPC) (8-21%), phosphatidylglycerol (PG) (1-4%) and phosphatidic acid (PA) (1-9%). The distribution of fatty acids was found to differ between phospholipids. Stearic acid was mainly present in the form of PC and LPC. Palmitic acid was present in the most abundant molecular species in PI, PG and PA whereas linoleic acid formed the most abundant molecular species in PE. © 2011 Elsevier Ltd. All rights reserved.


PubMed | CNRS Institute of Molecular Sciences and Laboratoire Of Biochimie Des Lipides
Type: Journal Article | Journal: Food chemistry | Year: 2015

An experimental investigation was carried out on Tunisian olive-fruits of Meski, Sayali and Picholine cultivars. -Tocopherol and fatty acids (FA) contents were analyzed, during both ripening and processing, according to the Spanish style. The relationship between oil, unsaponifiable and -tocopherol contents was determined only during ripening. A genetic effect on FA composition was observed throughout the sampling periods. The highest oleic acid content was found in Sayali cultivar at green stage (78.5% of total FA). -Tocopherol was positively correlated with unsaturated FA content (R=0.71, p<0.05), and oil amount (R=0.984; R=0.976; R=0.952, p<0.05 for Picholine, Sayali and Meski, respectively), but it was not correlated with unsaponifiable matter. In processed olive-fruits, the results showed primarily, that processing according to the Spanish style is not restricted to green olive-fruits but can be successfully used in cherry olives with guaranteed quality and nutritional value of processed product (Meski and Picholine) related to FA content. Secondly, both -tocopherol and FA amounts decreased during processing for all cultivars. This decrease was cultivar dependent. It was more pronounced in the black fruit than in the green one for the same cultivar. During fermentation, pH variation showed the same profile in all cultivars. Final pH values at the end of fermentation depend on the concentration of free FA (acidity) in the brine.

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