Polyphenol content and total antioxidant potential of selected Italian wines

The total antioxidant activity (TAA) of 13 typical Italian wines was determined (average 12.3 and 1.6 mM Trolox equivalents for red and white wines, respectively), and the resulting values were correlated with total phenols (1365-3326 and 96-146 mg/L for red and white wines, respectively), flavanols (203-805 and 11-49 mg/L, for red and white wines, respectively), and flavonols. Only the red wines contained appreciable amounts of flavonols (average 15.3 mg/L), with quercetin and rutin being the most abundant, followed by myricetin, kaempferol, and isorhamnetin accounting for only 0.7-3% of TAA. The TAA of investigated wines are well correlated with phenol (r = 0.9902) and flavanol (r = 0.9270) content. These results confirm that red wine polyphenols are in vitro significant antioxidants and may explain the beneficial effects of a moderate daily intake of red wines, probably through a sparing action of highly bioavailable vitamins C, E, and beta-carotene.