竹叶抗氧化物浸泡结合乳清分离蛋白涂膜对冷藏富硒虹鳟食用品质的影响

为延长冷藏富硒虹鳟的货架期,实验以3种浓度的竹叶抗氧化物溶液(AOBS,质量浓度分别为0.5%、1.0%和1.5%)分别浸泡富硒虹鳟鱼块,再进行乳清分离蛋白溶液(WPIS)涂膜,(25±1)°C下鼓风吹干表面水后置于4°C冰箱贮藏1、4、7、10和13 d,测定鱼块的pH值、TVB-N值、K值、菌落总数和嗜冷菌数、结合水分含量和水分状态,分析涂膜对冷藏富硒虹鳟鱼块品质的影响。结果显示,随着冷藏时间的延长,鱼块的pH值、TVB-N值、K值、菌落总数和嗜冷菌数显著增加,水分含量显著降低,结合水和不易流动水向自由水迁移。其中,1.0%AOBS+WPIS组的pH值、TVB-N值、K值、菌落总数和嗜冷菌数的增加速率和水分含量的减少速率最慢,结合水与不易流动水的比例最高。1.0%竹叶抗氧化物浸泡结合乳清分离蛋白涂膜,提升了乳清分离蛋白涂膜的保鲜效果,可有效抑制富硒虹鳟冷藏过程中品质的劣变,延长货架期。根据TVB-N值、K值和菌落总数,1.0%AOBS+WPIS组可延长富硒虹鳟货架期3 d。本研究可以为富硒虹鳟的低温贮藏技术提供科学指导。

Effects of whey protein isolate coating combined with bamboo leaf antioxidant soaking on quality attributes of Se-rich Oncorhynchus mykiss during cold storage

To prolong the shelf life of Se-rich rainbow trout, the fillets of Se-rich Oncorhynchus mykiss were respectively immersed into three antioxidant solutions of bamboo leaves (AOBS, 0.5%, 1.0%, and 1.5%), then coated using whey protein isolate solution (WPIS). The fillets coated were stored at 4 °C for 1, 4, 7, 10, and 13 d after the surface moisture was dried. The pH, TVB-N, and K values, total viable count (TVC), and total psychrophilic bacterial count (TPC) were measured, as well as moisture content and moisture state, to investigate the effect of coating on quality attributes of Se-rich O. mykiss during cold storage. The results showed that as cold storage time prolonged, the pH, TVB-N, and K values, TVC, and TPC of fillets significantly increased, while the moisture content significantly decreased (P<0.05). Besides, the bound water/immobilized water was transferred to free water. The pH, TVB-N, and K values, TVC, and TPC of fillets for 1.0% AOBS+WPIS group were lower than those for the other groups, as well as the percentage of bound water/immobilized water was transferred to free water, while the moisture content was higher than that of the other groups. These results suggested that the combination of whey protein isolate and antioxidant of bamboo leaves significantly enhanced the fresh-keeping effect of whey protein isolate coating, inhibited the quality deterioration and prolonged the shelf life of Se-rich O. mykiss. Furthermore, according to TVB-N and K values and TVC, 1.0% AOBS+WPIS group could prolong the shelf life 3 days for Se-rich rainbow trout at cold storage. The results can provide scientific reference for the low-temperature storage of Se-rich O. mykiss.