Abstract:Using low-value mackerel as the raw material and peptide content as the evaluation criterion, single-factor experiments and response surface methodology were employed to optimize the enzymatic hydrolysis conditions for this species. After determining the optimal enzymatic hydrolysis process parameters, further analyses were conducted on the antioxidant properties, amino acid composition, and molecular weight distribution range of the resulting hydrolyzed products. The results demonstrated that under a fixed feed-to-liquid ratio of 1:6, hydrolysis time was 4.5 h, hydrolysis temperature was 44°C, and enzyme addition amount was 4800 U/g. Under these conditions, the peptide content measured in the hydrolysate was 16.98 mg/mL. The hydrolysate contained 18 types of amino acids, with a total amino acid content of 30.47 g/L. Essential amino acids accounted for 46.00% of the total, with high concentrations of flavor-enhancing amino acids such as aspartic acid, glutamic acid, leucine, and lysine. Additionally, the relative molecular weight of peptides is mainly below 1500 Da, accounting for 87.50%. The research results provide a theoretical reference for the comprehensive utilization of high-value fish at high value.