Nutritional evaluation, bioconversion performance and phylogenetic assessment of black soldier fly (Hermetia illucens, Linn. 1758) larvae valorized from food waste

The black soldier fly (H. illucens) is a potential candidate species for the sustainable bioconversion of organic matter that endorses the concept of a circular economy. The nutritional evaluation of black soldier fly larvae (BSFL) reared in a food waste bioconversion system revealed a crude protein content of 41.44 ± 0.17 g/100g and crude lipid content of 35.69 ± 0.24 g/100g. Among the mineral content in BSFL, Ca (22.95 ± 0.91 g/kg) was present in the highest concentration, followed by P (5.47 ± 0.06 g/kg) and K (4.78 ± 0.081 g/kg). The fatty acid profile of BSFL oil showed a higher level of saturated fatty acids than unsaturated, with the highest level of lauric acid (C12:0). Vitamins such as retinol, vitamin D3, α-tocopherol, β-tocopherol, and γ-tocopherol were detected in larval oil. α-tocopherol was present in the highest concentration (80.39±4.02μg/g). The bioconversion performance of BSFL in terms of various parameters such as biomass yield, bioconversion efficiency, substrate reduction, and nutritional composition was evaluated. The bio-waste to larvae conversion ratio was 6.80, with a bioconversion efficiency of 24.31 ± 0.62 %. The overall substrate reduction by BSFL was 72.38 ± 1.37 %. In addition to amplification of mitochondrial partial COI gene for larval identification, comparative and phylogenetic analyses were performed. The phylogenetic analysis revealed that the specific haplotypic populations from Palaearctic, Oriental, Afrotropic, Australasian, and Nearctic biogeographic realms establish a closer relationship or single ancestral origin with the Indian haplotypes, which is probably associated with anthropogenic factors resulting in the cosmopolitan distribution of this new world originated wide-spectrum fly.