Polyphenols and oxidative stability of olive oil under different storage conditions

The effect of storage conditions of olive oil on the phenols and oxidative stability of oil was studied. Examinations were carrid out in some commercial olive oils obtained by pressing or by centrifugal extraction.The samples were stored at ambient temperature at day light and in the darkness, just as in the refrigerator. Before and after storage total phenols o-diphenols, chlorophyll, peroxide value and free fatty acids were determined in oils. Oxidative stability was also analysed at 98 oC and under UV-light. Phenol content in examined oils was different. Good quality oils, with no consideration of the optaining manner, had larger amount of phenols. After storage, the level of phenols had the highest decrease in samples stored at the day light. The oxidative changes, depending of phenol and chlorophyll content, were also the most expressed in these samples. Olive ois with higher amont of phenols hat better stability in almost all conditions of examination.