Effect of processing conditions on degree of hydrolysis, ACE inhibition, and antioxidant activities of protein hydrolysate from Acetes indicus.

Protein hydrolysate was prepared from Acetes indicus which is a major bycatch among non-penaeid prawn landings of India. Hydrolysis conditions (enzyme to substrate ratio and time) for preparing protein hydrolysates using alcalase enzyme were optimized by response surface methodology using central composite design. The optimum conditions for enzyme-substrate ratio (mL/100 g) of 1.57, 1.69, 1.60, 1.56, and 1.50 and for hydrolysis time of 97.18, 96.5, 98.15 min, 102.48, and 88.44 min were established for attaining maximum yield, degree of hydrolysis, 2,2-diphenyl-1-picrylhydrazyl, angiotensin I-converting enzyme-inhibiting activity, and metal-chelating activity, respectively. ABTS radical scavenging activity and reducing power assay of optimized protein hydrolysate were found to be increased with the increase in concentration. The higher value of 7.04 (μM Trolox/g), 87.95, and 77.24%, respectively for DPPH, ACE, and metal-chelating activity indicated that the A. indicus protein hydrolysates have beneficial biological properties that could be well-utilized in the application of functional foods and nutraceuticals. Graphical abstract ᅟ.