Contribution of metals, sulfur-dioxide and phenolic compounds to the antioxidant capacity of Carménère wines

Abstract

In this research, we determined the chemical composition of 37 Vitis vinifera cv. Carme´ne` re wines and established their antioxidant capacity (AC). A set of 26 measurements of chemical species potentially related to AC, including phenolic compounds, free and combined sulfites and iron, copper and manganese were obtained for each wine. The AC was estimated by DPPH and ORAC-FL methods. Statistical analyses showed good correlations between chemical profiles and AC values (DPPH r2 = 0.90 and ORAC-FL r2 = 0.87). The main chemical markers contributing to AC were the fraction of color given by free and copigmented anthocyanins (39.1%) for DPPH and gallic acid (30.7%) for ORAC-FL. These are a good indication of the complexity of the wine matrix, and the wide variety of substances possibly contributing to AC.