Compostos fenólicos e capacidade antioxidante de cultivares de uvas Vitis labrusca L. e Vitis vinifera L.

Abstract

Phenolic compounds including resveratrol, anthocyanins and other flavonoids and antioxidant capacity were evaluated for five grape cultivars cultivated in Minas Gerais (Brazil). The content of total phenolic determined by the Folin Ciocalteau method varied significantly, from 65 ± 1 to 390 ± 30 mg gallic acid equivalents. 100 g-1 of FW (Fresh Weight). The content of total anthocyanins quantified by HPLC varied from 6.7 ± 0.2 to 154 ± 4 mg of cyanidin equivalents. 100 gg-1 FW. Resveratrol was found in three cultivars, in contents from 0.022 ± 0.001 to 0.60 ± 0.03 mg. 100 gg-1 of FW. In addition to hydroxicynnamic acids, other flavonoids such as catechin, epicatechin, quercetin and kaempferol were also present. The antioxidant capacity was analyzed using the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging method and varied from 2.7 ± 0.1 to 19 ± 2 μmol trolox equivalents.gg-1 FW, showing good correlation with the content of total phenolics. The darker red grapes presented higher anthocyanin contents and consequently higher total phenolic contents and antioxidant capacity.