Comparison of TLC and spectrophotometric methods for evaluation of the antioxidant activity of grape and berry anthocyanins

Abstract

Variation of antioxidant activity was measured for differently prepared extracts of pressed residues (marc) from red wine making and production of blackcurrant and redcurrant juice. On the basis of previous tests ethanol and water were chosen as suitable solvents for preparing phenolic extracts from selected samples. Antioxidant activity was also measured for commercially available standards of the anthocyanins present in grapes and red- and blackcurrants, for example malvidin 3-glucoside (Mv3G), cyanidin 3-glucoside (Cy3G), delphinidin 3-glucoside (Dp3G), peonidin 3-glucoside (Pe3G), and petunidin 3-glucoside (Pt3G). Each standard and a mixture of all standards (concentration 250 μg mL −1 ) were analyzed. Two different analytical methods were used, spectrophotometry and TLC. In both methods DPPH was used as a source of stable free radicals with which components with antioxidant activity react. The strongest antioxidant activity was found for Cy3G, then for Pe3G and Mv3G, and the lowest was for Pt3G and D...