Dynamic changes in phenolic compounds, colour and antioxidant activity of mulberry wine during alcoholic fermentation

Dynamic changes in total phenolics (TP), total flavonoids (TF), total anthocyanins (TA), two main monomer anthocyanins, cyanidin-3-O-glucoside (C3G) and cyanidin-3-O-rutinoside (C3R), colour and antioxidant activities as well as correlations among these factors were investigated in mulberry wine during alcoholic fermentation. TP and TF increased rapidly from day 0 to 3 and showed unobvious changes from day 3 to 10, whereas TA, C3G and C3R increased first and then decreased. C3G and C3R reached their maximum at days 1 and 2, respectively; thereafter, C3G decreased rapidly, whereas C3R was more stable. Five colour parameters, L*, a*, b*, C* and H*, changed significantly from day 0 to 2 and showed unobvious changes from day 2 to 10. For antioxidant activity, changes of the scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH⋅) and reducing power were similar to changes of colour parameters. TP, TF, TA and C3R exhibited significant correlations (P < 0.01) with antioxidant activity, whereas C3G exhibited weaker correlations.