Abstract:

Based on the determination of protein content in juice of oysters and crams, and the optimization of enzymatic hydrolysis conditions for protein, enzymatic hydrolysis product of EHL1 was obtained. EHL1 was mixed with enzymatic hydrolysis liquid from scallop mantle (EHL2) to prepare compound seafood condiments. Results indicated that the juice of oysters and crams exhibited higher contents of polypeptides and proteins so that it was necessary for hydrolyzing them to obtain free amino acids as the most important components for sauce with delicious taste. The optimal conditions for enzymatic hydrolysis were hydrolysis at pH 3 and 60 ℃ for 5 h by acidic protease. The degree of hydrolysis was up to 0.929 at this optimal condition. The compound condiment was very delicious due to higher content of free amino acid nitrogen (15.6 mg/mL), which was higher than similar commodity (13.0 mg/mL) in market. Moreover, seven flavor amino acids including Gly, Asp, Ala, Glu, Thr, Ser and Pro were up to 50% of total free amino acids. Therefore, this investigation provided a new idea and method for comprehensive utilization of marine shellfish processing wastes.

Key words: clam juice, oyster juice, scallop mantle, enzymatic hydrolysis, degree of hydrolysis, compound seafood condiment