MODERATE ANTIOXIDATIVE EFFICIENCIES OF FLAVONOIDS DURING PEROXIDATIONOF METHYL LINOLEATE IN HOMOGENEOUS AND MICELLAR SOLUTIONS

The relative reactivities as well as the stoichiometric coefficients f or a number of flavonoids, catechols, and-for comparison-standard phen olic antioxidants were determined by analyzing the kinetics of oxygen consumption in organic and micellar systems, with peroxidation initiat ed by lipid- and water-soluble azo initiators. The results demonstrate d that the flavonoids did not behave as classic phenolic antioxidants such as alpha-tocopherol, but showed only moderate chain-breaking acti vities. The results were in line with other structure-activity relatio nship studies on the importance of the B-ring catechol structure, the 2,3-double bond, and the 3,5-hydroxy groups. The data are discussed in view of possible explanations of the deviations flavonoids reveal in their behavior compared with regular phenolic antioxidants.