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. Carménère wines and established their antioxidant capacity(AC). Aset of 26 measurements of chemical species potentially relatedto AC, including phenolic compounds, free & combined sulfites and iron, copper and  manganese, were obtainedfor 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 andORAC-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.