Optimization and characterization of enzymatic protein hydrolysis of Asiatic hard clam (Meretrix meretrix) compared with two other bivalve species

In this study, hydrolysate was produced from Asiatic hard clam (Meretrix meretrix) meat by enzymatic hydrolysis using Alcalase® 2.4 L and the optimum hydrolysis condition was determined. Optimization was carried out with face centred central composite design in response surface methodology. The optimum condition of hydrolysis conditions was determined by three levels and four independent variables, which were temperature °C (45, 55, 65°C), enzyme to substrate level, % v/w, (1, 1.5, 2%) time, (60, 120,180 mins) and pH of the substrate (7.5, 8.5, 9.5). Degree of hydrolysis (%) (DH) was chosen as the dependent variable. The optimum conditions for enzymatic hydrolysis of Asiatic hard clam meat were obtained at temperature ºC, enzyme to substrate concentration (ES), hydrolysis time and pH of 65°C, 1%, of 60 minutes and pH 7.5 respectively. In this condition, the predicted and actual value of degree of hydrolysis (DH) obtained were 25.79% and 26.32 ± 0.35% respectively. Suggested model for the enzymatic protein hydrolysis of Asiatic hard clam meat was a two-factor interaction (2FI) model. Asiatic hard clam hydrolysate powder contained of moisture, crude fat, ash, crude protein of 60.09 ± 0.88%, 7.36 ± 0.10%, 2.18 ± 0.29%, and 8.12 ± 0.02% respectively. DH (%) and proximate analysis of hydrolysate from Asiatic Hard clam was compared with hydrolysate of two different species of mollusk which was green mussel (Perna viridis) and blood cockle (Anadara granosa) from previous studies.