γ-聚谷氨酸复合TGase对鸡肉肌原纤维蛋白凝胶特性的影响

Effects of γ-polyglutamic acid combined with transglutaminase treatment on the gelatin properties of chicken myofibrillar protein

将不同质量分数的γ-聚谷氨酸(γ-polyglutamic acid,γ-PGA)和谷氨酰胺转氨酶(Transglutaminase,TGase)复合后添加到鸡肉肌原纤维蛋白中,通过测定肌原纤维蛋白热诱导凝胶硬度、弹性、保水性、白度值及凝胶中化学作用力的变化,研究γ-PGA复合TGase对鸡肉肌原纤维蛋白凝胶特性的影响。结果表明,γ-PGA和TGase对鸡肉肌原纤维蛋白凝胶特性都具有明显的改善作用,但将二者复合使用后对凝胶特性的改善作用更为明显,且在TGase质量分数为0.5%、γ-PGA质量分数为0.06%时,凝胶硬度、弹性和保水性都达到最大值;在TGase质量分数为0.7%、γ-PGA质量分数为0.12%时凝胶白度值最小。化学作用力分析表明,经γ-PGA和TGase处理后,疏水相互作用和非二硫共价键是维持凝胶三维结构稳定性的主要因素,离子键、氢键和二硫键是次要因素。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)图谱结果表明,TGase能够催化γ-PGA-蛋白质和蛋白质-蛋白质之间发生交联反应、形成大分子物质。

Different concentrations of γ-polyglutamic acid and transglutaminase were added to chicken myofibril- lar protein. In order to study the effects of γ-polyglutamic acid combined with transglutaminase on the myofibrillar protein heat-induced gelatin properties, the changes of hardness, springiness, water holding capacity, whiteness and the chemical force in the gelatin were measured. The results showed that γ-polyglutamic acid and transglutaminase had obvious effect on the gelatin properties of chicken myofibrillar protein. However, the improvement of gelatin properties was more obvious after the γ-polyglutamic acid and transglutaminase compounds were used. When the concentration of transglutaminase was 0.5% , the concentration of γ-polyglutamic acid was 0.06% , gelatin hardness, springiness, wa- ter holding capacity reached its maximum; when the concentration of transglutaminase was 0.7% , the concentration of γ-polyglutamic acid was 0.12% , gelatin whiteness value was the minimum. The chemical force analysis showed that after γ-polyglutamic acid and transglutaminase treatment, hydrophobic interaction and non-disulfide covalent bond were major factors in maintaining the stability of three-dimensional structure of the gelatin; ionic bonds, hydrogen bonds and disulphide bonds were the secondary factors. SDS-PAGE studies indicated that transglutaminase could cata- lyze the cross-linking reaction between γ-polyglutamic-protein and protein-protein to form macromolecular substances.