Author
Fayad Z. Sheabar
Bio: Fayad Z. Sheabar is an academic researcher. The author has contributed to research in topics: Fraction (chemistry). The author has an hindex of 1, co-authored 1 publications receiving 56 citations.
Topics: Fraction (chemistry)
Papers
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TL;DR: In this article, polyphenols were extracted from the rape of Israeli olive oil using hexane, acetone and ethanol in a simple sequential procedure yielding three fractions (A,B,C).
Abstract: Polyphenols were extracted from the rape of Israeli olive oil using hexane, acetone and ethanol in a simple sequential procedure yielding three fractions (A,B,C). Fraction A (extracted with hexane) contained few polyphenols (0.05%), while Fraction B (extracted with acetone) and Fraction C (extracted with ethanol) contained about 5% polyphenols each. Fractions B and C were also found to contain the highest ortho-di-phenol concentration (about 3%). The addition of purified Fraction B at a level of 100 ppm to refined olive or soybean oils partially inhibited the oxidative deterioration when the oils were stored in the dark at 100 C.
58 citations
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TL;DR: In this paper, the authors focus on the extraction of polyphenols from agricultural and industrial wastes, and summarize available data on the factors affecting their antioxidant activity and stability, and, in some cases, the reported major active compounds identified.
1,614 citations
TL;DR: In this article, the role of phenolic compounds as either antioxidants or substrates in browning reactions is examined. But the authors do not consider the effect of dietary intake and metabolic fate on the performance of browning.
1,233 citations
TL;DR: The measurement of antioxidant activities, especially of antioxidants that are mixtures, multifunctional or are acting in complex multiphase systems, cannot be evaluated satisfactorily by a simple antioxidant test without due regard to the many variables influencing the results.
Abstract: Antioxidant activity has been assessed in many ways. The limitation of many newer methods is the frequent lack of an actual substrate in the procedure. The combination of all approaches with the many test methods available explains the large variety of ways in which results of antioxidant testing are reported. The measurement of antioxidant activities, especially of antioxidants that are mixtures, multifunctional or are acting in complex multiphase systems, cannot be evaluated satisfactorily by a simple antioxidant test without due regard to the many variables influencing the results. Several test procedures may be required to evaluate such antioxidant activities. A general method of reporting antioxidant activity independent of the test procedure is proposed.
1,145 citations
TL;DR: The phenolic profile of OMW is complex, yet this complexity has not been fully exploited in the valorization of the waste, and most work on the bioactivity of O MW has focused on antioxidant and antimicrobial activities.
Abstract: Biophenols have attracted increasing attention during the past few years due to their biological activities and natural abundance and are potential targets for the food and pharmaceutical industries. Olive mill waste (OMW) is rich in biophenols and typically contains 98% of the total phenols in the olive fruit, making value addition to OMW an attractive enterprise. The phenolic profile of OMW is complex, yet this complexity has not been fully exploited in the valorization of the waste. Most work on the bioactivity of OMW has focused on antioxidant and antimicrobial activities. The analytical techniques used to identify and quantify active biophenols are also reviewed.
408 citations
TL;DR: In this paper, the total polar fraction and individual phenols present in virgin olive oil were tested for their antioxidant effect in refined olive oil, and the results showed that the phenols had little or no effect on the stability of the oil.
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.
347 citations