Influence of Sturgeon Protein Fractions on Active Peptide Generation via Enzymatic Hydrolysis

To identify the sturgeon protein component responsible for generating bioactive peptides, including antioxidant peptides and alcohol dehydrogenase (ADH) promoting peptides, sturgeon protein and its isolated protein components (sarcoplasmic, myofibrillar, and stromal proteins) were studied. Among the four isolated protein components, stromal protein demonstrated the highest susceptibility to enzymatic hydrolysis (P<0.05). Besides, pepsin and alkaline protease are the most effective enzymes for the hydrolysis of sturgeon protein to produce 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity peptides. For pepsin, the hydrolysate of sarcoplasmic protein has strong DPPH radical scavenging activity, while myofibrillar protein and stromal protein have better performance for alkaline protease. Moreover, sturgeon protein can produce an ADH-promoting peptide only under the action of trypsin. Myofibrillar protein can produce ADH-promoting peptides, while sarcoplasmic protein and stromal protein mainly produce ADH-inhibiting peptides. Therefore, the three protein components play a positive role in the production of antioxidant peptides. However, about the ADH-promoting peptides, only the myofibrillar protein plays a positive role, while the sarcoplasmic and stromal proteins play negative roles.