Changes in phenolic compounds and Rancimat stability of olive oils from varieties of olives at different stages of ripeness.
BACKGROUND
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.
Martínez Nieto
Leopoldo
L
Chemical Engineering Department, University of Granada, 18071 Granada, Spain.
Hodaifa
Gassan
G
Lozano Peña
Juan Luis
JL
D000383:Agriculture / Q000379:methods; D000975:Antioxidants / Q000032:analysis*; D001947:Breeding; D005419:Flavonoids / Q000032:analysis*; D005638:Fruit / Q000737:chemistry* / Q000254:growth & development; D016014:Linear Models; D031658:Olea / Q000737:chemistry* / Q000145:classification / Q000254:growth & development; D000069463:Olive Oil; D010636:Phenols / Q000032:analysis*; D010938:Plant Oils / Q000032:analysis*; D059808:Polyphenols; D013045:Species Specificity; D013649:Taste
D000975:Antioxidants; D005419:Flavonoids; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D059808:Polyphenols