This study evaluated the safety and nutritional values of an edible insect (Gryllus bimaculatus, G) as an alternative food source. Three different pre-treatments were performed: steamed G without drying (SG), steamed G with hot air drying (SHG), and steamed G with freeze drying (SFG). An 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay of the RAW 264.7 cells and a determination of the heavy metal content were performed. In addition, the general compositions, as well as the minerals, amino acids, and fatty acids contents of the three kinds of samples were analyzed. From the MTT assay and heavy metal content, these samples (SG, SHG, and SFG) were not harmful as an edible food. In addition, the nutritional composition of SG were lower than those of SHG and SFG because the moisture of SHG and SFG was reduced during drying processing. In the case of the general composition, SHG and SFG contained high protein, low carbohydrate, and very low fat levels. The contents of Ca, P, and Mg of SHG and SFG were high. The content of essential amino acids, particularly branched-chain amino acids (BCAAs), were high in SHG and SFG. Furthermore, glutamic acid, which has been used to improve the taste in the food industry, was high in SHG and SFG. The ratios of saturated to unsaturated fatty acids of SHG and SFG were 1:2, each. Overall, Gryllus bimaculatus is a safe food material with high BCAAs, high mineral, low carbohydrate, and low fat contents.

Keywords: edible insect, Gryllus bimaculatus, alternative food source, nutritional evaluation