茶多酚改性胶原蛋白-壳聚糖复合膜对冷藏斜带石斑鱼的保鲜效果

研究茶多酚改性后的胶原蛋白-壳聚糖复合膜对冷藏斜带石斑鱼的保鲜效果。在4℃冷藏条件下,采用空白对照、胶原蛋白-壳聚糖复合膜、茶多酚改性胶原蛋白-壳聚糖复合膜3种方式处理样品并贮藏20 d,以K值、肌动球蛋白含量、巯基(—SH)含量、Ca~(2+)-ATPase活性以及p H值、硫代巴比妥酸(thiobarbityric acid,TBA)值、挥发性盐基氮(total volatile basic nitrogen,TVB-N)值、菌落总数、感官评定值作为研究指标。结果表明:胶原蛋白-壳聚糖复合膜、茶多酚改性胶原蛋白-壳聚糖复合膜处理组斜带石斑鱼的巯基含量、肌动球蛋白含量、Ca~(2+)-ATPase活性和感官评定值均显著高于对照组(P0.05),而K值、p H值、TVB-N值、菌落总数均显著低于对照组(P0.05),且茶多酚改性胶原蛋白-壳聚糖复合膜处理组的效果优于胶原蛋白-壳聚糖复合膜处理组,其中3个处理组的TBA值的差异性不显著(P0.05)。茶多酚改性胶原蛋白-壳聚糖复合膜处理组鱼肉的肌动球蛋白变性和巯基含量降低缓慢、Ca~(2+)-ATPase活性下降受到阻碍、TVB-N值等理化指标变化以及细菌总数生长受到抑制。说明在4℃冷藏条件下,茶多酚改性胶原蛋白-壳聚糖复合膜处理组能有效延缓斜带石斑鱼的腐败变质,保鲜效果更明显。

Preservation Effect of Collagen-Chitosan Blend Film Modified by Tea Polyphenols on Grouper (Epinephelus coioides) Fillets Stored at 4 ℃

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.