Degradation of various fruit juice anthocyanins by hydrogen peroxide

Abstract

Degradation kinetics of anthocyanins was studied in sour cherry nectar, pomegranate and strawberry juices at high hydrogen peroxide (H2O 2) concentrations (9.31-27.92 mmol l-1) at 10-30°C and in only sour cherry nectar at low H2O2 concentrations (0.23-2.33 mmol l-1) at 20°C. Degradation of anthocyanins followed the first-order reaction kinetics. Sour cherry anthocyanins were the most resistant to H2O2, followed by pomegranate and strawberry anthocyanins. Degradation of anthocyanins was also studied in sour cherry nectar and pomegranate juice in the presence of ascorbic acid at 60 and 80 mg l-1 concentrations at 20°C. At 80 mg level, ascorbic acid significantly accelerated the degradation of anthocyanins in sour cherry nectar at 4.65, 6.98 and 9.31 mmol l-1 H2O2 concentrations. In contrast, ascorbic acid at both 60 and 80 mg levels protected the anthocyanins from degradation by H2O2 in pomegranate juice.