Effects of Ca~(2+)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 e-(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.