Media type: E-Article Title: Changes in phenolic compounds and Rancimat stability of olive oils from varieties of olives at different stages of ripeness Contributor: Nieto, Leopoldo Martínez; Hodaifa, Gassan; Lozano Peña, Juan Luis Published: Wiley, 2010 Published in: Journal of the Science of Food and Agriculture, 90 (2010) 14, Seite 2393-2398 Language: English DOI: 10.1002/jsfa.4097 ISSN: 0022-5142; 1097-0010 Origination: Footnote: Description: AbstractBACKGROUND: Recently, diets rich in natural foods and food‐derived components, such as phenolic compounds, have received a great deal of attention because they are perceived as ‘safe’ and ‘non‐medicinal’. In fact, some are known to function as chemopreventive agents against oxidative damage, cerebrovascular disease, and aging.RESULTS: Phenolic compounds, natural antioxidants present in virgin olive oil, play an important role in oil quality by contributing significantly to protecting oil stability against oxidation. In addition, polyphenols are the main contributors to olive oil bitterness, astringency and pungency. The data were fit by linear regression, giving Rancimat stability (h) = 0.18× Total polyphenols (mg L−1) in the virgin olive oil.CONCLUSIONS: The practice of harvesting ripe olives as soon as possible to produce oils of high phenolic contents and thus high oxidative stability implies bitter and piquant oils, this being admissible for oils of some varieties but detrimental to others appreciated in the market for being more fruity and sweeter. Copyright © 2010 Society of Chemical Industry