Effect of ethanol treatment on the structural, techno-functional, and antioxidant properties of edible insect protein obtained from Tenebrio molitor larvae

Edible insect-derived proteins have attracted considerable attention in the food industry owing to their excellent nutritional and bio-functional activities. Herein, ethanol (20, 40, 60, and 80 %)-treated Tenebrio molitor protein (ETMP) was prepared, and its structural, techno-functional, and antioxidant properties were assessed. As the ethanol concentration increased, the molecular weight of the ETMP decreased, and alpha-helix content decreased whereas that of beta-sheet increased, affecting the secondary structure. Ethanol treatment also resulted in changes in the techno-functional properties of edible insect proteins. ETMP showed significant 2,2 '-Azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt radical-scavenging activity (p < 0.05), and its antioxidant activity effectively increased the viability of Vero cells damaged by oxidative stress; 20 % ethanol treatment induced the highest antioxidant activity. In conclusion, our results suggest that appropriate ethanol treatment (20 %) increases the antioxidant activity of edible insect proteins, suggesting their potential in food as an alternative protein resource and functional food with excellent antioxidant activity.