Enzymatic hydrolysis of black cricket (Gryllus assimilis) proteins positively affects their antioxidant properties.

The development of innovative ingredients through biotechnological routes has established insect proteins as an emerging source of bioactive peptides. The current study aimed to evaluate the antioxidant properties of black cricket (Gryllus assimilis) protein hydrolysates produced using the proteases Flavourzyme 500L, Alcalase 2.4L, and Neutrase 0.8L, either individually or in binary/ternary combinations. The enzymatic hydrolysis promoted an increase of approximately 160% in total antioxidant capacity and 93% in the ferric reducing antioxidant power. The isolated use of the enzyme Flavourzyme 500L showed the most prominent positive effect on the antioxidant properties, presenting an IC value of 455 and 71 µg/mL for DPPH and ABTS radicals scavenging activities, respectively. This sample was composed mainly of small peptides (MW < 3 kDa), in which the antioxidant properties increased after fractionation by ultrafiltration. Gel electrophoresis analysis showed protein hydrolysates composed mainly of polypeptide chains with a mass of less than 14 kDa. Finally, the enzymatic treatment proved to be an efficient process to improve the antioxidant properties of black cricket proteins, increasing the possibility of applying these hydrolysates as bioactive ingredients in food or nutraceutical products. PRACTICAL APPLICATION: Insects represent an alternative source of proteins. Their modification through hydrolysis allows for the acquisition of compounds with great potential in industrial applications, such as functional ingredients or for nutraceutical purposes. The use of our experimental design proved to be an adequate tool for defining the best process conditions required for increasing the attainment of biologically active compounds.