Nutritional composition of black soldier fly (<i>Hermetia illucens</i>) prepupae reared on different organic waste substrates

TLDR

Black soldier fly larvae convert organic waste into edible biomass, and their nutritional composition may vary with the substrate used. The study aimed to raise larvae on four different substrates—chicken feed, vegetable waste, biogas digestate, and restaurant waste—to assess resulting nutritional differences. Prepupae and substrates were freeze‑dried and subjected to proximate, amino‑acid, fatty‑acid, and mineral analyses, with protein content measured between 399 and 431 g kg⁻¹ dry matter across treatments. Protein content and amino‑acid profiles were similar across substrates, but prepupae from digestate had markedly lower ether extract and higher ash, whereas those from vegetable waste, chicken feed, and restaurant waste had higher ether extract and lower ash, with all treatments showing high C12:0 fatty acids and overall comparable protein quality, indicating substrate‑dependent variations in fat and mineral content. © 2016 Society of Chemical Industry.

Abstract

Black soldier fly larvae are converters of organic waste into edible biomass, of which the composition may depend on the substrate. In this study, larvae were grown on four substrates: chicken feed, vegetable waste, biogas digestate, and restaurant waste. Samples of prepupae and substrates were freeze-dried and proximate, amino acid, fatty acid and mineral analyses were performed.Protein content of prepupae varied between 399 and 431 g kg-1 dry matter (DM) among treatments. Differences in amino acid profile of prepupae were small. On the other hand, the ether extract (EE) and ash contents differed substantially. Prepupae reared on digestate were low in EE and high in ash (218 and 197 g kg-1 DM, respectively) compared to those reared on vegetable waste (371 and 96 g kg-1 DM, respectively), chicken feed (336 and 100 g kg-1 DM, respectively) and restaurant waste (386 and 27 g kg-1 DM, respectively). Prepupal fatty acid profiles were characterised by high levels of C12:0 in all treatments.Since protein content and quality were high and comparable for prepupae reared on different substrates, black soldier fly could be an interesting protein source for animal feeds. However, differences in EE and ash content as a function of substrate should be considered. © 2016 Society of Chemical Industry.