转谷氨酰胺酶对鳙鱼糜热诱导胶凝特性的影响

Effect of Transglutaminase on Heat-induced Gel Properties of Bighead Carp (Aristichthys nobilis) Surimi

以鳙鱼糜为对象,测定添加不同转谷氨酰胺酶(TGase)量的鱼糜在热加工过程中凝胶动态流变特性、胶凝温度、凝胶形成活化能、分子质量分布、凝胶强度和溶解性的变化,以研究TGase对鳙鱼糜热诱导胶凝特性的影响。结果表明:鳙鱼糜在热诱导凝胶形成过程中,其胶凝温度(Tgel)和胶凝活化能(Ea)随着TGase添加量的增大而降低,而溶解度和肌球蛋白重链(MHC)条带百分比随着TGase添加量的增大而降低后趋于稳定。添加TGase可降低鱼糜发生胶凝所需的能垒,使MHC之间更易形成ε-(γ-谷氨酰)赖氨酸共价键。而鱼糜凝胶的破断强度、凝胶强度、持水性和储能模量(G′)则随TGase添加量的增加呈现先上升后下降的趋势,当TGase添加量为28.08U/100g鱼糜时,其凝胶强度最高、失水率最小。与对照组相比,添加TGase 28.08U/100g鱼糜的鳙鱼糜凝胶强度提高2.7倍,失水率减少46%,G′提高2.5倍。当TGase添加量超过28.08U/100g鱼糜,鳙鱼糜凝胶的G′、破断强度、凝胶强度和持水性下降。适当添加TGase可降低Ea和Tgel,明显提高鳙鱼糜的凝胶强度和持水性。

In order to explore the impact of TGase on heat-induced gel properties,the effect of transglutaminase（TGase） on the dynamic rheological properties,gelation temperature（Tgel）,gel activation energy（Ea）,distribution of molecular weight,gel strength and solubility from bighead carp（Aristichthys nobilis） surimi during heating processing were evaluated.Results showed that Tgel and Ea decreased along with the increase of TGase concentration,while solubility and MHC intensity decreased and tended to be stable afterwards.The weaken of energy barriers in thermal gelation cause more formation of ε-（γ-Glu） lys bonds induced by TGase.While the breaking strength,gel strength,water-holding capacity and storage modulus G′ revealed an initial increase,and then decreased along with the increase of TGase concentration.In contrast,when TGase concentration was 28.08 U/100 g of surimi,the gel strength was the highest and the expressible moisture was the lowest.Compared with the control group,the gel strength increased by 2.7 times;expressible moisture decreased by approximately 46%,and G′ exhibited a 2.5 fold enhancement.When the TGase was added more than 28.08 U/100 g of surimi,G′,the breaking strength,the gel strength and water-holding capacity exhibited an obvious reduction.An appropriate concentration of TGase could significantly improve the gel strength and water-holding capacity of bighead carp surimi.