钙离子对白鲢鱼糜热诱导凝胶化的影响

本文通过不同浓度钙离子对白鲢鱼糜凝胶的凝胶特性、溶解率及MHC影响的研究,探讨了Ca2+增强白鲢鱼糜凝胶特性的机理及在白鲢鱼糜中的适宜添加量。结果表明,低浓度的钙离子(10、20mmol/kg)可以激活内源性转谷氨酰胺酶,催化MHC之间共价交联形成ε-(γ-Glu)-Lys共价键,导致鱼糜凝胶溶解率降低,MHC减少,凝胶特性增强,且钙离子的最适添加量为20mmol/kg;但是50mmol/kg的钙离子浓度使MHC的交联受阻,致使鱼糜凝胶特性降低,溶解率增加;当钙离子浓度达到80mmol/kg时,钙离子可与鱼糜蛋白之间形成蛋白质-钙-蛋白质的钙桥结构,使凝胶变硬,弹性降低。

Effects of Ca2+ on Heat-induced Gelation of Silver Carp Surimi Gel

Effects of different Ca2+ concentrations on gel-forming ability,solubility and MHC of surimi gel were investigated.Calcium ions with low concentration(10,20mmol/kg)activated the endogenous transglutaminase(TGase).TGase catalyzed polymerization of myosin heavy chain(MHC)via formation of ε-(γ-glutamyl)-Lysine non-sulfide covalent bonds,leading to decreasing of solubility and MHC of surmi gel and the increasing of surimi gel-forming ability.The optimum Ca2+ concentration is 20mmol/kg.However,when Ca2+ concentration is 50mmol/kg,cross-links of MHC are inhibited,which cause the decreasing of gel-forming ability and the increasing of solubility of surimi gel.Protein-Ca-protein bridge structure is formed between calcium ions and surimi protein when Ca2+ concentration is up to 80mmol/kg,so surimi gel becomes harder and less elastic.