Radical-scavenging capacity of several Italian red wines

The main object of the present study was to investigate the correlation between the radical-scavenging powers (measured by evaluating the quenching of the stable 2,2-diphenyl-1-picrylhydrazyl radical) of seven red Italian wines from different geographical origins, and their contents of total phenols and of anthocyanins and proanthocyanins, as well as of other antioxidant components (ethanol, ascorbic acid, sulphur dioxide and glutathione). All red wines tested in our study showed evident radical-scavenging properties. In particular the radical-scavenger efficiencies of these wines may be attributed, in a significant number at least, to their content of total phenols, and are affected by alcohol only in a marginal way. Furthermore, the antioxidant efficiency of red wines tested appears to be largely influenced by the proanthocyanidin level, with anthocyanins playing a minor role. Finally, ascorbic acid, thiol groups and SO2 (antioxidant compounds present in red wines especially as consequence of the wine-making processes) play only a minor role in the radical-scavenging power of the red wines under investigation. In conclusion, the present findings support the results from several experimental and epidemiological studies, suggesting that the supply of antioxidant phenols through a moderate daily consumption of red wines may provide additional protection against in vivo oxidation of cellular biomolecules.