Characterization of Osborne-extracted proteins from black soldier fly (Hermetia illucens) larvae: Functional properties, allergenicity, bioactivities, and acute toxicity

• Black soldier fly (Hermetia illucens) larvae (BSFL) protein fractions from Osborne method were protein-nutritious. • Glutelin (GLU) from BSFL proteins had the greatest foaming and emulsifying capacities. • Digested prolamin (DPRO) and digested glutelin (DGLU) showed the best antioxidant while DPRO showed anti-inflammation. • Tropomyosin-1 (TPM1), an allergenic protein, was potentially eliminated after in vitro digestion. • BSFL protein fractions from Osborne method showed no acute toxicity in rats. Edible black soldier fly ( Hermetia illucens ) larvae (BSFL) contain high-quality protein. Crude BSFL extracts have been studied for alternative dietary protein developments. This study examined four BSFL protein types including albumin (ALB), globulin (GLO), prolamin (PRO), and glutelin (GLU), extracted by Osborne method. Their chemical composition, physical properties, and biological activities were investigated. Each protein exhibited different amino acid compositions and physical properties. Notably, GLU exhibited excellent foaming and emulsifying capacities. To mimic human consumption, all proteins were undergone in vitro digestion, and their biological activities were subsequently measured. The allergenic protein known as invertebrate tropomyosin-1 (TMP1), which was detected in BSFL, ALB, and GLO, was undetecTable after the digestion, suggesting a reduction in allergenicity. Digested PRO (DPRO) presented the strongest ferric reducing activity, while digested GLU (DGLU) was particularly effective in scavenging DPPH and ABTS radicals. DPRO also showed anti-inflammation in macrophage cells and exhibited cytotoxicity against A549, HepG2, and SW620 cell lines. Moreover, no sign of acute toxicity was observed in rats following a single administration of ALB, GLO, or GLU at 2 g/kg bw or PRO at 5 g/kg bw over 14 days.These findings indicated that BSFL-derived proteins obtained by Osborne method are high-quality functional proteins with promising physical and biological activities having the potential use as a sustainable alternative dietary protein and a functional food.