Influência do solvente no conteúdo total de polifenóis, antocianinas e atividade antioxidante de extratos de bagaço de uva (Vitis vinifera) variedades Tannat e Ancelota

Abstract

Different solvent systems were applied in order to determine the extraction efficiency of compounds with antioxidant capacity from grape bagasse, an important by-product from wine production. The quantification of total phenolics, anthocyanins, and antioxidant activity was carried out in grape bagasse extracts of Tannat and Ancelota varieties from the region of Videira, state of Santa Catarina. The antioxidant activity was determined by ABTS, FRAP, and β-carotene/linoleic acid system methods. Extracts from acidified aqueous solutions of acetone and ethanol in different concentrations (v/v) showed higher yield in aqueous solutions of acetone 50 and 70% for Tannat variety and acetone/ethanol 50% for Ancelota variety, respectively. The total phenolic contents in acetone 50 and 70% were higher in both varieties while the anthocyanin contents in these varieties were higher in ethanol 50 and 70%. The antioxidant activity was higher in acetone 50 and 70% for Tannat variety and acetone/ethanol 50 and 70% for Ancelota variety by the ABTS method. Regarding the reduction power performed by the FRAP method, it was higher in acetone 70% in both varieties. During the oxidation inhibition power assay, the addition of 100 and 200 μL of ethanolic extracts 50% of Tannat and Ancelota varieties showed higher efficiency since it was almost two times higher than acetonic extracts. Keywords: byproducts; extraction; oxidation; reduction power.