Antioxidant and Ace Inhibitor Potential of Stripe Trevally Fish (Selaroides leptolepis) Hydrolysate

Abstract

This study aimed to investigate the potency of fish protein hydrolysates (FPH) of stripe trevally fish (Selaroides leptolepis) as antioxidant and ACE inhibitor. The FPH was produced through enzymatically hydrolysis using protease produced by Bacillus licheniformis, a collection of Research and Development Center for Marine and Fisheries Product Processing and Biotechnology (RDCMFPPB). The FPH was fractionated using ultrafiltration membranes with molecular weight cut off (MWCO) of 10, 5 and 3 kDa. The hydrolysis degree, protein content, peptide content, antioxidant activity and Angiotensin-converting enzyme (ACE) inhibitor were observed. The result showed that FPH had maximum hydrolysis degree of 63.91% reached after 6 hours hydrolysis with protein content of 27.43 mg/mL and peptide content of 223.32 mg/mL. That FPH showed antioxidant activity (IC50) of 1941.06 ppm and ACE inhibitor of 87.82% at test concentration of 10 mg/mL. In the ultrafiltration step, the higher molecular cut off used, the higher protein content and peptide content. The lower molecular weight of the hydrolysate, the better antioxidant  and ACE inhibitor activity. The best fractionation that produce potential product to be used as anti-hypertension was in mixture peptides between 3-5 kDa. The IC50 antioxidant activity was 1336.96 ppm and percentage of ACE inhibitor was 97.15% % (with a concentration of 10 mg/mL). From the results, protein hydrolysate of stripe trevally fish produced by enzymatic hydrolysis using local protease was potential as a functional ingredient, particularly as antihypertensive agent.