BIOGENESIS OF FUSTY DEFECT IN VIRGIN OLIVE OILS

The biogenesis of ''fusty'' defect was studied by chemical and microbi al analyses on olives stored in piles for different times and their re sulting oils. The fusty defect was perceived by tasters after four day s of storage. The quali-quantitative composition of oil volatile fract ion was a very suitable way to emphasize metabolites produced by micro organisms involved during the fruit storage. Some volatile compounds, such as 2- and 3- methyl butan-1-al, their corresponding alcohols and propionic acid, 2-methyl propionic acid and 3-methyl butanoic acid, we re produced. At he same time, it was observed a dramatic development o f Clostridium sp. and, in a lower proportion, of Pseudomonas sp. Furth ermore, during the storage the evident softening of fruits has to be a ttributed to microorganisms in rapid growth belonging to Enterobacter so. and moulds, that have in its enzymatic store pectinoltic enzymes.