牦牛肌原纤维蛋白与热改性大豆分离蛋白共凝胶条件的优化

Optimization of Co-Gelation Conditions of Yak Myofibrillar Protein and Heat Modified Soy Protein Isolate

牦牛肉是纯天然食品原料,然而牦牛肉蛋白资源的开发利用不够,特别是利用质构重组技术将牦牛肉中的肌原纤维蛋白和大豆分离蛋白用于开发凝胶产品鲜见研究报道。本研究以牦牛肌原纤维蛋白(myofibrillar?protein?isolate,MPI)与热改性大豆分离蛋白(soybean protein isolate,SPI)为原料,分别采用单因素试验和正交试验设计,研究SPI-MPI溶液体积比、SPI热改性温度、离子强度和转谷氨酰胺酶(TGase)用量对共凝胶硬度、弹性和持水性的影响。单因素试验结果表明:改变4个因素条件均能显著地提高热改性SPI-MPI溶液的凝胶性能,各因素对共凝胶特性综合指标影响的主次顺序为SPI-MPI溶液体积比>TG用量>离子强度>SPI热改性温度。正交试验结果表明形成共凝胶的最优条件是:SPI-MPI溶液体积比1∶9、SPI热改性温度100℃、TG用量50?U/g、不添加镁离子。

Yak meat has not yet been fully exploited as an excellent source of natural protein, especially yak myofibrillar the combined application of which with soy protein isolate （SPI） in gel products by texture and structure recombination has not yet been reported. The objectives of this study were to investigate the effects of myofibrillar protein isolate （MPI）/SPI ratio, heating temperature of SPI, ion concentration, and transglutaminase （TGase） concentration on co-gelation properties and consequently to obtain the optimized gelation conditions for MPI and SPI. All the four factors had a significant positive on gelation properties of thermally modified SPI and MPI in the decreasing order of SPI/MPI ratio （by volume） 〉 TG concentration 〉 ion concentration 〉 heating temperature of SPI. Using an orthogonal array design, the optimal cogelation conditions were determined as follows： SPI/MPI ratio, 1：9; heat modification temperature for SPI, 100 ℃; TGase concentration, 50 U/g; and no added magnesium.