Effect of glycosylation, acylation and pyranylation at cyanidin C‐ring on its interaction with vitamin C in apple juice beverage matrix

BACKGROUND Synchronous degradation between anthocyanin and vitamin C was found in fruit and vegetable juice matrices. To investigate whether the C‐ring of anthocyanin is the key site of this interaction, cyanidin with four different C‐ring modifications (3‐glucosylation, 3,5‐diglucosylation, 6″‐malonylation, pyranylation) was added to vitamin C‐containing apple juice, and the changes of anthocyanin retention, vitamin C retention, color, antioxidative activity and differential metabolites were analyzed. RESULTS The anthocyanin retention was in the order of pyranylation >6″‐malonylation >3,5‐diglucosylation >3‐glucosylation. The vitamin C retention was in the order of 6″‐malonylation > pyranylation >3,5‐diglucosylation >3‐glucosylation. The order of color stability was the same as that of anthocyanin retention, and the order of antioxidative activity was opposite to that of vitamin C retention. The results showed that modification at the C‐ring limited the activity of anthocyanin, and suggested that the C‐ring was one of the key sites for anthocyanin and vitamin C interaction. The shared differential metabolite of all apple juice matrices added with different anthocyanins was trans ‐hinokiresinol, which was likely generated from anthocyanin skeleton reacted with certain compounds in apple juice. CONCLUSION This study showed that modification of the anthocyanin C‐ring could affect the anthocyanin and vitamin C interaction to some extent, which provided valuable insights for the application of anthocyanin C‐ring modification in shelf‐life quality control of typical fruit and vegetable beverages with the coexistence of anthocyanin and vitamin C.