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 byproduct 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 dosedependent 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 valueadded nutritive food ingredients.