Preparation of enzymatic hydrolysate from crayfish shells and its application in the processing of crayfish whole balls

Objective: For enhancing the flavor characteristics and nutritional value of crayfish balls, and enriching the diversity of crayfish processed products. Methods: Determined the process of preparing the enzymatic hydrolysate from crayfish shell using compound enzymatic by single-factor and orthogonal array design. The nutritional quality of crayfish whole balls containing enzyme hydrolysate lyophilized powder and crayfish meat was analyzed. Results: The optimum condition for the preparation of crayfish shells enzymatic hydrolysate solution showed that 1 g crayfish shells powder with 0.5 mL of lactic acid was pretreated at 60 ℃ for 40 min. The dosage of compound enzymatic （papain and flavor protease mass ratio was 3∶1） was 5% （mass fraction）, the enzymatic hydrolysis temperature was 60 ℃, time was 4 h, and solid/liquid ratio was 1∶100 （g/mL）, and the protein extraction efficiency in the enzymatic hydrolysis was 64.69%. The content of heavy metals in enzyme hydrolysate lyophilized powder was in line with the limit of heavy metals in aquatic products, and contains calcium, magnesium, iron, selenium and other macro and trace elements required by the human body. Its composition analysis showed that the enzymatic hydrolysate lyophilized powder had a certain nutritional value, which could increase the fresh flavor of the food and met the safety standards. The nutrition and texture analysis of crayfish balls showed that the crayfish whole balls had high protein content, rich in a variety of amino acids, comprehensive in nutrition, unique flavor, and with good viscoelasticity and chewiness. Conclusion: The crayfish whole balls added with crayfish shell enzyme hydrolysate lyophilized powder and crayfish meat have a certain nutritional value, which enriches the variety of crayfish ready-to-eat products, improves the utilization rate of whole crayfish.