Antioxidant activity of selected Spanish wines in corn oil emulsions

Wines contain phenolic compounds that may be useful for preventing lipid ox idation as dietary antioxidants. This study was aimed at evaluating the ant ioxidant activity in corn oil emulsions of seventeen selected Spanish wines and two California wines. The inhibition of hydroperoxide formation at 10 muM gallic acid equivalents (GAE) varied from 8.4% to 40.2% with the red wi nes, from 20.9% to 45.8% with the rose wines, and from 6.5% to 47.0% with t he white wines. The inhibition of hydroperoxide formation at 20 muM GAF: va ried from 11.9% to 34.1% with the red wines, from 0.1% to 34.5% with the ro se wines, and from 3.3% to 37.2% with the white wines. The inhibition of he xanal formation at 10 muM GAE varied from 23.6% to 64.4% with the red wines , from 42.7% to 68.5% with the rose wines, and from 28.4% to 68.8% with the white wines. The inhibition of hexanal formation at 20 muM GAE varied from 33.0% to 46.3% with the red wines, from 11.3% to 66.5% with the rose wines , and from -16.7% to +21.0% with the white wines. The antioxidant effect de creased with increasing concentration. This antioxidant activity was relate d to the five main groups of phenolic compounds identified in wines by HPLC . The relative antioxidant activity correlated positively with the total ph enol content of wines (by the Folin-Ciocalteu method and by HPLC), benzoic acids, anthocyanins, flavan-3-ols, and flavonols, for the inhibition of hyd roperoxides and hexanal at 10 and 20 muM GAE.