Changes in fatty acid composition and antioxidant content of olive fruits after preharvest methyl jasmonate and abscisic acid treatments

A new procedure to minimize the degradation of fatty acids and polyphenols during the olive fruit storage is here proposed. This procedure is based on preharvest treatments of ‘Arbequina’ and ‘Picual’ olive trees with methyl jasmonate and abscisic acid. As a result, total phenolic content increased in all treated ‘Arbequina’ olive fruits as compared with controls. In contrast to ‘Arbequina’ fruit, only abscisic acid resulted in total phenolic content increase in ‘Picual’ olive fruits. Regarding the antioxidant activity, neither of the phytoregulators was effective. Fatty acid composition was also affected by both of them in ‘Arbequina’ and ‘Picual’ fruits. Saturated fatty acid decreased with both methyl jasmonate and abscisic acid whereas unsaturated fatty acids increased significantly in treated olive fruits. Olive fruits with higher antioxidant activity exhibited higher unsaturated/saturated fat ratio. The application of phytoregulators to olive tree can be interesting to the oil industry particularly when a delay in oil processing occurs and olive fruits have to be stored.