Edible insect protein for food applications: Extraction, composition, and functional properties

Abstract This study sought to establish an optimized procedure for extraction of protein from microwave‐dried larvae of an edible insect, Hermetia illucens (HIL), and to determine and compare the amino acid (AA) component, intrinsic fluorescence (IF), and physicochemical/functional properties (PFPs) of protein isolates. Box–Behnken's design with the Box–Wilson methodology was applied in the optimization process. Following single‐factor investigations, the relational analysis indicated that the polynomial model could be used to illustrate the influence of extraction parameters on protein yield. Response–surface plots showed that extraction variables influenced ( p < .05) protein yield of HIL. The optimized extraction (optimized protocol [OP]) conditions with highest yield (64.44%) were time—59.43 min, alkaline solution to sample ratio—24.85:1.00, and temperature—52.23°C. The protein extract obtained using the OP, compared with a modified protocol (MP) (with conditions: 60 min, 15:1 alkaline solution to sample ratio, and 40°C) showed content of 80.42 ± 0.90% and 76.91 ± 0.91%, respectively ( p < .05). The AA‐scores were above that recommended by FAO. Variations existed between OP and MP extracts regarding PFPs, consistent with IF/AA‐values. The optimized extraction process was feasible, and the functional properties of HIL protein could be enhanced/modified for different food formulations. Practical applications Hermetia illucens (HIL), an edible insect rich in protein, is one most promising insect species for food applications with extra benefits to the environment. Consumption, however, is limited by many due to association of insects to vermin/dirt. The need to increase consumption globally is paramount, as there is high demand on the already scarce protein sources available worldwide. Extracting the constituents of edible insects for novel/food applications is a promising approach to upturn global consumption in the next 2–3 decades where humans may rely on insect protein. The success of scale‐up processing in this regard depends on process conditions for better yields. Therefore, determining an optimized technique for extraction of protein from HIL larvae was investigated as well as physicochemical/technofunctional properties, and fluorescence attribute. The extraction approach was feasible and the outcome of the study may benefit industry in extraction and/or modification of edible insect protein in novel applications.