Condition-dependent effects of phenolic Copigments on anthocyanin stability in Chinese bayberry juice: An HPLC-degradation kinetic study

This study systematically investigated the condition-dependent effects of six phenolic copigments on the stability of cyanidin-3-O-glucoside (C3G) in model and actual Chinese bayberry juice using spectroscopic, kinetic (HPLC-based), and colorimetric analyses. Flavonoid glycosides, particularly myricitrin, exhibited significant protective effects on C3G in model juice at 90 °C ( P < 0.05). However, an unexpected reversal was observed: in model juice stored at 37 °C, certain flavonoids and phenolic acids significantly accelerated C3G degradation, reducing its half-life to approximately one-fifth of the control value, whereas the actual juice matrix effectively prevented this reversal. In the presence of ascorbic acid (AA), all copigments mitigated C3G degradation. The protective effect of myricitrin was concentration-dependent, and global nonlinear modeling confirmed significant interactions among copigment type, matrix, temperature, and AA ( P < 0.001). These findings provide preliminary insights for copigment selection in Chinese bayberry juice processing.