Effect of various compounds on virgin olive oil stability measured by rancimat

Phenolic and orthodiphenolic compounds together with carotenoids, tocophero ls, pigments, and fatty acids were tested for their antioxidant effect in 7 9 samples of virgin olive oils cv. Picual and Hojiblanca. A linear regressi on based on the oleic/linoleic ratio and the contents of phenols and tocoph erols showed a good correlation (adjusted-R-2 = 0.91) with the stability me asured by Rancimat, later verified with an external text set (adjusted-R-2 = 0.95). A tentative study on the percentage contribution of each chemical variable to stability is discussed. The contribution of phenolic and orthod iphenolic compounds was around 51%, the composition of fatty acids 24%, and in less percentage alpha-tocopherol, carotenoids, and chlorophylls. No eff ect, or very little, was shown by beta- and gamma-tocopherols.