Abstract:To optimize the process of softening crayfish (Procambarus clarkii) shells, the effects of malic, acetic, and citric acids crayfish shell softening were evaluated based on indicators such as the decalcification rate, shell hardness, and sensory score of softened crayfish tails. Multiple regression models were established using the Box-Behnken response surface methodology, with the acid concentration, soaking time, and solvent-to-solid ratio as independent variables and decalcification rate and hardness of crayfish shells as dependent variables to optimize the process of using acid to soften crayfish shells. The results showed that organic acids reduced the hardness of crayfish shells and that the dried products of softened crayfish were accepted by consumers when the decalcification rate of crayfish shells reached at least 48.00%. Among the three organic acids, citric acid was the most effective softener of crayfish shells. When the mass concentration of citric acid, soaking time, and solvent-to-solid ratio were 70 g/L, 63.84 min, and 2.01:1 (V/m), respectively, the decalcification rate and hardness of softened crayfish shells were 56.21% and 14.36 (a reduction of 48.99%), respectively. After acid treatment, the hardness of crayfish shells decreased significantly, and the palatability of crayfish was increased, increasing the appeal of the crayfish products to consumer. The findings provide a theoretical basis and technical support for producing ready-to-eat shell-on crayfish products.
