Antioxidant activity of virgin olive oil phenolic compounds in a micellar system

The antioxidant activity of two virgin olive oils, obtained from the same o live (Olea europaea sativa) batch but processed with different hammer crush ing conditions, was evaluated by measuring their protective action towards linoleic acid peroxidation in a micellar system. The antioxidant efficiency (AE) of the oil phenolic fraction was higher when the olives were processe d with a higher hammer crusher rotation rate. HPLC analysis demonstrated th at one of the main derivatives of oleuropein, indicated as 3,4-DHPEA-EDA (t he dialdehydic form of elenolic acid Linked with 3,4-dihydroxyphenylethanol ), is present only in the oil with higher AE. 3,4-DHPEA-EDA showed the grea test antioxidant ability among virgin olive oil phenols. Its greater effici ency in the micellar system in comparison with 3,4-dihydroxyphenylethanol ( 3,4-DHPEA) is related to its greater lipophilicity. It is suggested that th e behaviour in the water-micellar environment is representative of that in a real system such as tomato-based sauce with added virgin olive oil. (C) 1 999 Society of Chemical Industry.