罗非鱼副产物蛋白水解肽的呈味分析

为了探究罗非鱼副产物蛋白水解物中滋味活性物质的来源，该研究以罗非鱼的鱼皮、鱼头和鱼骨为原料，采用中性蛋白酶、菠萝蛋白酶、风味蛋白酶、复合蛋白酶、木瓜蛋白酶和碱性蛋白酶分别对三种副产物进行酶解，分析比较水解度、分子量、前体蛋白与滋味活性物质的关系。结果表明：三种罗非鱼副产物经过风味蛋白酶水解酶水解8 h后获得最高水解度，分别为14.29%、23.7%和31.86%。经过木瓜蛋白酶水解的副产物酶解液均呈现出显著苦味或酸味，而鱼头经过碱性蛋白酶酶解得到的水解产物具有鲜味，鱼骨则经过菠萝蛋白酶水解得到鲜味，鱼皮经过中性蛋白酶水解表现出鲜味和酸味，但鱼头却呈现出苦味。通过LC-MS/MS鉴定，胶原蛋白、肌原纤维蛋白以及肌浆蛋白是罗非鱼副产物酶解液滋味活性肽的重要味觉活性前体，这些滋味肽的分子量大部分小于1500 u，肽段中疏水性氨基酸残基对罗非鱼副产物滋味的形成具有重要作用，其中蛋氨酸在酶解液的鲜味的形成中起重要贡献。

Taste Analysis of Protein Hydrolysates from Tilapia By-product

In this paper, the source of taste-active compounds from tilapia by-products (skin, head, and bone) was investigated. Three types of by-products were hydrolyzed by neutrase, bromelain, flavorzyme, protamex, papain, and alcalase. The relationships between the degree of hydrolysis (DH), molecular weight (MW) distribution, precursor protein, and the characteristics of taste-active compounds were analyzed. The results showed that the highest degree of hydrolysis of the three tilapia by-products was obtained after hydrolysis with flavorzyme for 8 hours, which were 14.29%, 23.7% and 31.86% respectively. The by-products of papain hydrolysis showed significant bitter or sour taste, while the hydrolysate of fish head hydrolyzed by alkaline protease had umami taste, the fish bone hydrolyzed by bromelain had umami taste, and the fish skin hydrolyzed by neutral protease showed umami and sour taste, but the fish head showed bitter taste. By LC-MS/MS, collagen, myofibril proteins, and some sarcoplasmic proteins were important taste-active precursor of the potential taste peptides of tilapia by-products. The MW of most of these potential taste peptides was lower than 1500 u. The hydrophobic amino acid residues in peptides played an important role in the formation of the taste of tilapia by-products, in which methionine contributed to generate umami taste in the by-products hydrolysates.