Effects of the Acid- and Alkali-Aided Processes on Bighead Carp (Aristichthys nobilis) Muscle Proteins

The objective of this study was to investigate the effects of the acid- and alkali-aided processes on bighead carp (Aristichthys nobilis) muscle protein as compared with the conventional washing method. Acid- and alkali-aided processes resulted in higher protein recoveries than conventional washing method. In textural profile analyses, the highest hardness and cohesiveness were observed in the gels prepared by conventional washing and alkali-aided processing (p < 0.05). No endothermic peak was found in the differential scanning calorimetry thermogram of protein isolates after acid- and alkali-aided processes. The hydrophobic interactions and disulfide bonds were the main chemical bonds to maintain the stability of the gel matrix, while the sulfhydryl group in bighead carp muscle was apt to be activated during alkali-aided processing. The α-helical content of actomyosin decreased remarkably after the acid- and alkali-aided processes (p < 0.05). Overall, there is a potential to apply the alkali-aided processing to extract proteins from bighead carp muscle for the production of surimi-based seafoods.