Enzymolysis pretreatment followed by fermentation is a novel method to prepare shrimp sauce with high quality from by-products in crayfish (Procambarus clarkii)

A rapid fermentation process after enzymolysis pretreatment was applied to prepare shrimp sauce using crayfish heads. The optimal fermentation process through orthogonal experiments was obtained: 35 °C, 25 % koji addition, and 5 % salt addition. During fermentation, the content of amino acid nitrogen reached its maximum value of 7.00 mg/mL at 20 days. The content of volatile base nitrogen was increased to 281.64 mg/100 mL at 30 days. A total of 32 fatty acids were detected in the shrimp sauce, and the oleic acid and pentadecanoic acid existed during 0-9 days of fermentation. A total of 16 free amino acids were detected in shrimp sauce, mainly glutamic acid, leucine, aspartic acid, lysine, and alanine. Flavor and essential amino acids accounted for 51.09 % and 42.79 % at 30 days, respectively. Enzymolysis pretreatment followed by fermentation is a feasible method to prepare high-quality shrimp sauce rich in amino acids and fatty acids from crayfish heads.