Effect of Transglutaminase on the Emulsifying Activity Index and Gel Properties of Common Carp Myofibrillar Protein

Objective:The aim of this study was to investigate the impact of transglutaminase (TG) on the emulsifying properties and heat-induced gelation properties of myofibrillar proteins from common carp so as to provide theoretical basis for improvement the quality characteristics of surimi products. Methods:Myofibrillar proteins suspensions (final protein concentration of 40 mg/mL) were prepared. TG were added to the suspensions to obtain final concentrations of 0, 0.1%, 0.2%, 0.3%, and 0.4% (w/v) after mixing, emulsification activity and gel property index of the protein solution were measured. Results:Emulsifying activity decreased (p<0.05) as TG concentration increased, however turbidity greatly increased (p<0.05) when TG was added. The results of protein rheological properties suggested that the TG increased the storage modulus (G') (p<0.05), decreased initial gel temperature and increased the protein denaturation temperature. Compared to control, the gel water holding capacity first decreased (p<0.05) when TG concentrations at 0.1% and then had no significant difference with increased TG concentrations. TG addition significantly decreased the gel whiteness (p<0.05). Gel texture results showed that gel quality was greatly improved (p<0.05) with the TG addition. As the TG levels increased, gel hardness and springiness increased significantly (p<0.05). Conclusion:TG addition decreased emulsifying ability and improved the Gel properties of myofibrillar protein.