CHANGES IN SICILIAN VIRGIN OLIVE OIL DURING STORAGE WITH PARTICULARLY HIGHLIGHTED BIOPHENOL COMPONENTS

In order to study the changes during storage of virgin olive oils extracted from Biancolilla, Cerasuola and Nocellara del Belice cultivars, homogeneous batches of olive fruits were processed by using different malaxing temperatures. Also, traditional three-phases decanter with different water temperatures was used for oil separation from the solid phase. Oil samples were shared out amber glass bottles and stored in the dark at cellar temperature. The changes in turbidity and in lipid substrate were monitored within the year of olive fruit processing. For each sample the results showed changes of conventional chemical parameters (free acidity, peroxide and UV absorption values), of total phenolic content and some of hydrophilic phenols contents. Oil turbidity decreased with the lower rate for the olive oil by processing at colder temperature. The evolution of total phenols, alpha-tocopherol and hydrophilic phenols contents showed that the conditions of storage play an important role for oxidative stability of olive oils.