Chemical composition, energy and nutritional values, digestibility and functional properties of defatted flour, protein concentrates and isolates from Carbula marginella (Hemiptera: Pentatomidae) and Cirina butyrospermi (Lepidoptera: Saturniidae)

Edible insects constitute a potential source of alternative proteins as a food supplement. The present study aimed to investigate the chemical composition, energy and nutritional values, the digestibility and functional properties of Carbula marginella (Thunberg) and Cirina butyrospermi (Vuillet) defatted flour, protein concentrates, and isolates. Carbula marginella has shown the highest content of protein (41.44%), lipid (51.92%), calcium (33.92 mg/100 g) and sodium (185.84 mg/100 g) while the highest contents of carbohydrate (34.54%), ash (4.77%), iron (31.27 mg/100 g), magnesium (150.09 mg/100 g), and potassium (1277 mg/100 g) have been observed for C. butyrospermi. Linoleic (30.23%), palmitic (27.54%), oleic (26.41%) and stearic (8.90%) acids were the most dominant fatty acids found in C. marginella. Cirina butyrospermi was characterized by high levels of oleic (27.01%), stearic (21.02%), linolenic (20.42%), palmitic (13.06%), and linoleic (8.01%) acids. Protein and essential amino acid contents of the protein isolates in both insect species were 1.7-2 times higher than that of their defatted flours. The protein isolate of C. marginella exhibited the highest protein digestibility (87.63%), while the highest fat absorption capacity (8.84 g/g) and foaming capacity (48.40%) have been obtained from the protein isolate of C. butyrospermi. These findings indicate that the protein concentrates and isolates of C. marginella and C. butyrospermi have great potential for industrial applications.