鲢鱼皮改性明胶复合多肽锌对草鱼的保鲜作用

Effect of Modified Gelatin from Silver Carp Skin Combined with Peptide-Zn Complex on Preservation of Grass Carp

研究鲢鱼皮谷氨酰胺转胺酶(transglutaminase,TGase)改性明胶复合多肽锌对冷藏草鱼段的保鲜效果。通过测定草鱼段在4℃冷藏过程中感官评分、硫代巴比妥酸(thiobarbituric acid,TBA)、挥发性盐基氮(total volatile basic nitrogen,TVB-N)、p H值和菌落总数等指标,评估不同处理条件下草鱼品质的变化情况。结果表明,改性明胶及其复合多肽锌对草鱼均有明显的防腐保鲜作用,有效抑制了草鱼TBA值、TVB-N值、p H值的升高以及菌落总数的增长。与海藻酸钠多肽锌处理的涂膜组草鱼相比,改性明胶单独涂膜组的保鲜效果与之相当,而改性明胶复合多肽锌膜组在贮藏前6 d的保鲜效果明显比海藻酸钠复合多肽锌组更好,一级及二级鲜度贮藏期均比海藻酸钠多肽锌复合组延长了3 d。因此,与海藻胶相比,改性鱼皮明胶是一种良好的涂膜材料,可以有效提高水产品的保质期。

The coating preservation of gelatin modified by transglutaminase（TGase） combined with peptide-Zn complex from silver carp skin on grass carp was studied. Sensory evaluation, thiobarbituric acid（TBA）, total volatile basic nitrogen（TVB-N）, p H value and total bacterial count were measured to study the quality changes of grass carp with different treatments during cold storage. The results showed that modified gelatin alone and its combination with peptide-Zn complex prepared from silver carp skin protein hydrolysate were both effective in preventing deterioration and preserving the quality of grass carp by significantly inhibiting the increases in TBA value, TVB-N value and p H value and restraining bacterial growth. Modified gelatin was comparable to sodium alginate combined with peptide-Zn complex in terms of efficacy. However, compared with sodium alginate combined with peptide-Zn complex, grass carp had a better quality on the 6th d of storage after being coated with modified gelatin combined with peptide-Zn complex. As a result, the quality of grass carp remained at the first and second grades both for 3 more days. In conclusion, modified gelatin combined with peptide-Zn complex was a more effective coating for preserving the quality of aquatic products when compared with the combination with sodium alginate.