Three monovarietal virgin olive oils obtained from olives grown under biological agricultural system, in Portugal, with different ripening
stages, were studied in what concerns the parameters usually related with oxidation status (total polyphenols, tocopherols, chlorophylls
and carotenoids, peroxide values, oxidative stability, specific extinction coefficients K232 and K270 and titratable acidity). A total
of 18 samples were analyzed: seven from Cv. Cobranc¸osa (maturation indices 1–7), five from Cv. Madural (maturation indices 3–7) and
six from Cv. Verdeal Transmontana (maturation indices 1–6). Oxidative stability and polyphenols profile presented high correlation coef-
ficients. Given this high correlation, a numerical method was developed and evaluated to predict total polyphenols contents in olive oil.
The method is based on the kinetic equation of the oxidation process in the presence of antioxidants and on Rancimat profiles. Total
polyphenols contents obtained with this method were similar to those obtained by the Folin-Ciocalteau method.
