Influence of Dacus Oleae infestation on flavor of oils, extracted from attacked olive fruits, by HPLC and HRGC analyses of volatile compounds

The authors have examined the influence of the Dacus Oleae infestation on the aroma of the oils obtained from olives of Coratina and Nebbio varieties at different levels of attack. The results obtained indicated a worsening of the qualitative level of the oils obtained from increasing percentages of infested olives; these were found to have a great decrease of phenolic substances and higher contents of both volatile alcohols and aldehydes with an unpleasant sensation. Of particular interest was hexanal/total volatile alcohols ratio, in which having been well correlated with the extent of infestation, would permit one to establish in an objective manner, if and how much the olives from which an oil has been extracted have suffered a Dacus attack.