Varietal differences in the phenolic content and superoxide radical scavenging potential of wines from different sources

Thirty-one wine samples differing in their-origin of production and vintages were analyzed for total phenolic content, total and free sulfur dioxide contents, and superoxide radical scavenging potentials. The polyphenol content of red wine ranged from 735.9 to 2858 ppm, and that of white wine was in the range 259.4-720.5 ppm. Total sufur dioxide content ranged from 21.9 to 270.7 ppm, and had no correlation to the color of the wine: Superoxide radical scavenging activity values ranged from 39.3 to 215.9 units/mL for the white wine, and those of red varieties were similar to 5-10 times higher. No correlation was observed between the free and total sulfur dioxide contents in the different wine samples tested and their superoxide radical scavenging activity values. A direct correlation between the color of the wine (r = 0.7517), its phenolic content (r = 0.9908), and the ability of the wine constituents to scavenge superoxide radical was, however, established by a simple regression analysis.