BIOGENERATION OF VOLATILE COMPOUNDS IN VIRGIN OLIVE OIL - THEIR EVOLUTION IN RELATION TO MALAXATION TIME

The volatile composition of oils obtained from fruits of two Italian v arieties, Coratina and Frantoio, using different malaxation times of p astes was determined. The results show that the biogeneration of aroma components was very fast and took place just after cell disruption, o wing to the activation of enzymes contained in the fruit. The cleavage by heterolytic hydroperoxide lyase is the most important process in b oth varieties considered and gives rise to C-6 compounds which represe nt the major compounds of the olive oil aroma. C-6 aldehydes and alcoh ols increase with the prolonging of malaxation, whereas esters conside rably decrease after 30 min. In addition, C-5 alcohols, C-5 carbonyl c ompounds, and pentene dimers have been detected in the volatile compos ition of virgin olive oils.