Effects of a defatting process on the thermal stabilities and volatile compound profiles of proteins isolated from Protaetia brevitarsis larvae

To ensure food security for the continuously growing worldwide population, it is necessary to promote the use of underutilized foods in food products. In this context, we evaluated the effect of a protein defatting process, which was performed using n-hexane, on the physicochemical characteristics, thermal stabilities, and aromatic profiles of proteins extracted from an edible insect, Protaetia brevitarsis. The defatting process decreased the color values (L*, a*, b*; P < 0.01) and apparent viscosities of the solutions of the extracted proteins and increased their pH values (P < 0.01), but did not affect their thermal stabilities. Additionally, defatting reduced the cohesiveness, gumminess, and chewiness (P < 0.01), but did not affect the hardness or springiness of the product. Furthermore, it lowered the levels of alcohols, aldehydes formed by lipid oxidation, and some hydrocarbons that have a negative physiological effect or impart an off-flavor to this food. Moreover, a simultaneous increase in the number of hydrocarbons with a pleasant flavor was observed. Collectively, the defatting process had a beneficial effect. It altered the properties of the insect proteins, and could potentially promote the use of edible insects as a protein source in the food industry.