Effects of oxidation and browning of macerated white wine on its antioxidant and direct vasodilatory activity

Abstract Although naturally produced macerated white wines are increasingly popular, their biological effects are rarely studied. As wines containing no preservatives, they are highly susceptible to oxidation after bottle opening. Our aims were therefore: (1) to compare the antioxidant and direct vasodilatory activity of standard (W) and polyphenols-rich macerated white wine (PW); (2) to examine effects of oxidation and browning of PW, associated with its exposure to air for 24 (24 h-OxPW) and 48 h (48 h-OxPW), on measured biological activities. Total phenolics content, direct vasodilatory and antioxidant activity of PW were much higher than those of W. Overall effects of up to 48 h-exposure to air on levels and composition of examined phenolics were minor. Similarly, exposure to air and associated browning did not affect maximal vasodilatory and antioxidant activity of PW. Vasodilatory potency, however, increasingly weakened with exposure to air as oxidized samples had higher half maximal effective concentrations than intact PW.