en Biotechnology Biotechnology پژوهشي Orginal research papers 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 (<em>p</em><0.05). The results from this study showed that carotenoprotein from banana shrimp have both <span dir="RTL">radical scavenging activity</span> and antihypertensive properties and a high content of essential amino acids, and could be good source for value-added nutritive food ingredients. Rainbow trout viscera, Protease, Banana shrimp, Carotenoprotein, Radical scavenging, Activity, ACE inhibitory 1510 1525 http://jifro.ir/browse.php?a_code=A-10-3561-1&slc_lang=en&sid=1 G. Taghizadeh Andevari taghizadeh.gh@gmail.com 100319475328460041358 100319475328460041358 No Tarbiat Modares university M. Rezaei rezai_ma@modares.ac.ir 100319475328460041359 100319475328460041359 Yes Tarbiat Modares university M. Tabarsa m.tabrsa@modares.ac.ir 100319475328460041360 100319475328460041360 No Tarbiat Modares university T. Rustad turid.rustad@ntnu.no 100319475328460041361 100319475328460041361 No Department of Biotechnology and Food Science, Norwegian University of Science and Technology, Trondheim, Norway.