TEA PHENOLS - ANTIOXIDANT EFFECTIVENESS OF TEAS, TEA COMPONENTS, TEA FRACTIONS AND THEIR BINDING WITH LIPOPROTEINS

Phenols in tea are responsible for its antioxidant activity. The pure catechins and phenolic acids found in tea are more powerful than the a ntioxidant vitamins C, E and beta-carotene in an in vitro lipoprotein oxidation model. Comparison of the tea fractions indicated that both c atechins and theaflavins contribute to the teas' antioxidant character istics. Black and green teas were not significantly different in pheno l content, in antioxidant strength as measured by IC50, or in antioxid ant potential as measured by the phenol antioxidant index (PAOXI). The PAOXI of teas was significantly higher than grape juices and wines. T ea catechins and both green and black tea exhibited potent lipoprotein -bound antioxidant activity. Phenol antioxidants from tea were calcula ted to be a large source of antioxidants in the U.S. diet. (C) 1998 El sevier Science Inc.