Carotenoprotein from by-product of banana shrimp (Penaeus merguiensis) extracted using protease from viscera of rainbow trout: antiradical and angiotensin I-converting enzyme inhibitory activity

Carotenoprotein as a marine bioactive compound was recovered from banana shrimp by-product using protease from rainbow trout viscera at various levels (5 and 15 units/g shrimp shell). The yield of carotenoprotein increased with increasing enzyme concentration up to 51.6%, which was consistent with increasing degree of hydrolysis. Protein and lipid content of the hydrolysate was 79.6 and 9.4 percent, respectively. The hydrolysate had a high nutritional value with a high amount of essential amino acids (465 mg/g) compared to the control (254 mg/g). The carotenoprotein exhibited a dose-dependent increase in antiradical activity measured by two in vitro assays, with an efficiency of 94 and 57 percent for DPPH and ABTS scavenging activities, respectively. Protease-extracted carotenoprotein showed higher ACE inhibiting effect than the control at different concentrations (p<0.05). The results from this study showed that carotenoprotein from banana shrimp have both radical scavenging activity and antihypertensive properties and a high content of essential amino acids, and could be good source for value-added nutritive food ingredients.