Effect of polyphenols extracted from (Olea europaea. L) solid residues and leaves on the oxidative stability of a commercial olive oil

In this study, polyphenols have been extracted from solid residues and leaves of olive tree (Olea europaea L) in order to assess this vegetable biomass by evaluation of their capacity as a natural antioxidants. The anti-oxidative activity was tested by addition of these extracts on commercial olive oil samples. The olive oil stability has been measured by accelerated oxidation under a simulated storage conditions (60°C/15 days). The change in the oxidation state was followed by measuring of the free acidity, peroxide value (PV) and the specific extinction at 270 nm. The assessment of enriched oils showed that polyphenols from olive by-products play a key role in reducing of oxidative deterioration of the oil. The results suggest the introduction of olive leaves and solid residues extracts in food preparation, both during storage or heating food, for better preservation.