Techno-Functional and Antioxidant Properties of Extracted Protein from Edible Insects

Abstract

Due to the recent increase in the human population and the associated shortage of protein resources, it is necessary to find new, sustainable, and natural protein resources from underutilized edible insects. This study sought to establish an optimized procedure for three extraction techniques [distilled water (E1), water with ultrasonic-assisted (E2), and chemical (E3): 0.25 M NaOH; pH 13.6] of protein from edible caterpillars (Gynanisa maja and Gonimbrasia belina) and cricket (Gryllus bimaculatus), and further to characterize the amino acid component and the techno-functional and antioxidant properties of the extracted proteins. The extraction efficiency of E3 was over 150%, with its proteins having higher oil- and water-holding capacities (3.69–5.75 and 2.36–3.08 g/g, respectively), foaming (foam capacity: 47–61%, foam stability: 17–84%), emulsion (emulsion activity: 41–51%, emulsion stability: 6–41%), and high amounts of essential amino acids. Protein extracts using E2 and E1 had higher solubility (>60%) over a wide pH range. The proteins and the hydrolysates obtained from the various insects through the different extraction methods had substantial antioxidative activities (<1.0 mg/mL). The hydrolysates from G. maja extracted by E3 and hydrolyzed by enzymes (pepsin + trypsin) had the highest antioxidant activity (56.7 μg/mL). The extraction approaches were feasible with unique specificity in their outcomes, which may benefit food industry in extraction and/or modification of edible insect protein in novel applications for different product formulations.