Antioxidant effectiveness of selected wines in comparison with (+)-catechin

The antioxidant effectiveness of selected wines and pure (+)-catechin were determined using three different methods. The radical scavenging potential was investigated using alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radical, scavenging, the reducing power was determined using ferric reducing/antioxidant power (FRAP) assay and P-carotene bleaching (BCB) method. Six red and four white wines from different grape cultivars were analyzed. Unpaired test between FRAP, DPPH, and BCB analysis of red and white wines showed significant difference. Different reducing/ antioxidant power of red and white wines was elucidated in view of their different phenolic composition. As expected, the red wines had much higher flavonoid, anthocyanin, and catechin content than white wines. There was no significant difference between nonflavonoids phenols. All analyzed wines demonstrate significant antioxidant capacity with FRAP test. The average FRAP of red wines was almost 10-fold higher than the average FRAP of white wines. The reducing ability of red wines can be directly correlated with its flavonoid and catechin concentration. The relative antioxidant efficiency of pure (+)-catechin in FRAP assay was same as for ascorbate and Trolox. (C) 2003 Elsevier Ltd. All rights reserved.