Phenolic compounds in oil obtained from Olea europaea and anti-Dacus treatments

The influence of two different antiparasitic treatments on the phenolic fraction of virgin olive oil was studied. These treatments were carried out to fight Dacus oleae infestation. HPLC analysis was performed on the phenolic fraction of samples obtained from treated and untreated olives, picked during two successive seasons. During the first season, characterized by low infestation and favourable climatic conditions, treatments did not significantly improve oil quality. The total amount of phenolic compounds decreased in samples obtained from treated olives, and this reduction affected more significantly ortodiphenolic compounds having an antioxidative activity. During the following season, high infestation and abundant autumn rains caused a marked decrease of phenolic compounds even in oils obtained from untreated olives. This time, however, anti-Dacus treatments led to an improvement of some oil quality indexes