Abstract: The preservative effect of collagen-chitosan blend film modified by tea polyphenols on the quality of Epinephelus coioides was evaluated. The samples from the blank control group, collagen-chitosan blend film group (T1) and blend film group modified by tea polyphenols (T2) were stored at 4 ℃ for 20 days. The K value, actomyosin content, total sulfhydryl content (–SH), Ca2+-ATPase activity, pH, total volatile basic nitrogen (TVB-N) value, thiobarbityric acid (TBA) value, total viable count (TVC), and sensory evaluation were measured during storage. The results indicated that total sulfhydryl content, actomyosin content, Ca2+-ATPase activity and sensory evaluation in T1 and T2 treatments were significantly (P < 0.05) higher than those in the blank control group, while a significant decrease in K value, pH, TVB-N, and TVC was observed (P < 0.05), indicating that the preservative effect of T2 was superior to that of T1. Furthermore, the difference in TBA was not significant (P > 0.05) among these groups. T2 treatment slowed down the degradation of actomyosin, blocked the reduction of –SH content and Ca2+-ATPase activity, and inhibited the increase of TVB-N and TVC as well as the growth of total bacterial counts. These observations suggested that the blend film modified by tea polyphenols could effectively retard the spoilage of Epinephelus coioides at 4 ℃, being advantageous in preservation.

Key words: grouper, collagen, blend film, tea polyhenols, preservation