Bioactive properties of Kilka (Clupeonella cultriventris caspi) fish protein hydrolysates

摘要

Whole common Kilka fish was hydrolyzed separately using four commercial enzymes, Alcalase, Neutrase, Protamex at 50 degrees C and Pepsin at 37 degrees C for 30, 60 and 90min. Degree of hydrolysis, angiotensin-I-converting enzyme (ACE) inhibitory activity and antimicrobial activity of each hydrolysate against Gram-negative (Escherichia coli, Salmonella enteritidis) and Gram-positive (Staphylococcus aureus, Listeria innocua) bacteria were studied. Results showed that the degree of hydrolysis for all enzymes was in the range of 2.63-3.36%. Electrophoresis profiles of the Kilka protein hydrolysates showed that most of produced peptides were in the range of 30D but Alcalase and Neutrase had a better performance in the production of low molecular weight peptides in the range of 10D. This led to increase the antimicrobial activity against the examined bacteria at the concentration of 200 mu g/mL peptide solution. The Neutrase enzyme produced hydrolysate with the highest ACE inhibitory activity (53%+/- 1.8 at 500 mu g/mL). Antimicrobial activity of Kilka protein hydrolysates using Protamex and Pepsin was lower than the others due to lack of considerable amount of small peptides. The current research has demonstrated that the peptides derived from the enzymatic hydrolysis of Kilka fish protein in optimum conditions are capable of being converted to antimicrobial and antihypertensive agents to be used in functional foods.