Degradation kinetics and pathways of red raspberry anthocyanins in model and juice systems and their correlation with color and antioxidant changes during storage

Degradation kinetics and pathways of red raspberry anthocyanins in both model systems and juice during storage at 37 degrees C were compared to understand degradation mechanism of red raspberry anthocyanins. The two main anthocyanins, cyanidin-3-glucoside (Cy-3-glc) and cyanidin-3-sophoroside (Cy-3-soph) in juice degraded faster than those in model system, indicating that the coexisting components in juice may have an acceleration effect on anthocyanin degradation. Anthocyanins in juice followed similar degradation pathways as that in model system. HPLC ESI MS analysis of the degradation products suggested the breakdown of anthocyanins to colorless small molecular constituents led to the color loss of juice. Moreover, these compounds were insufficient to preserve the antioxidant capacity of juice, and the loss of antioxidant activity of the juice could not be compensated. Our results provided useful information for understanding anthocyanin degradation in real foods and its relation to the quality and bio-activity changes.