Optimization of Response Surface Design and Blood Pressure-Lowering Constitutive Effect of Enzymatically Degraded Peptides from Tuna Dark Meats

Purpose - In order to optimize the process of enzymatic degradation of peptides from tuna dark meat and also to explore the hypotensive activity of the peptides. Design/Methodology/Approach - Based on methodology, trypsin was used to treat the dark meat of tuna, to study the effects of material-liquid ratio, enzyme addition, temperature and time on the degree of hydrolysis (%) of the dark meat, to optimize the enzymatic process by using one-factor and response surface experiments, and to study the blood pressure-lowering activity of the enzymatic peptides obtained by in vitro experiments. Findings - The results show that the optimal enzyme digestion temperature of the peptide by tuna dark meat trypsin was 50.44 ℃, the amount of enzyme added was 2.08%, and the enzyme digestion time was 5.89 h. The in vitro experiments yielded an IC50 value of hypertension inhibitory activity of 2.635 mg/ml, which proved that the enzyme-digested peptide had blood pressure-lowering activity, and provided a basis for the further utilization of the enzyme-digested peptide. Research Implications - In the management of this paper, high-value utilization of aquatic resources is achieved by effective enzymatic digestion of tuna processing by-products to obtain bioactive peptides through enzymatic digestion technology.