Characteristics of lipid fractions of larvae of the black soldier fly Hermetia illucens

Abstract

The lipid fraction of larvae of the black soldier fly Hermetia illucens was shown to contain lauric acid (38.43 wt %) and its esters, azelaic and sebacic acids, and azelaic acid dibutyl ester. The dominant compound in the group of identified glycerides was lauric acid monoglyceride (0.70 wt %). Glycerides were also represented by triglycerides and diglycerides of lauric acid. Sterols were represented primarily by phytosterols (over 75%), the major of which was alpha-sitosterol (45%). The identified lipid complex composition is apparently determined by the biological characteristics of the fly Hermetia illucens and ensures antibacterial defence of larvae and stability of lipids at changing ambient temperature.

Effect of rearing substrate on growth performance, waste reduction efficiency and chemical composition of black soldier fly (Hermetia illucens) larvae

“…We can argue that the high SFA presence could be ascribed to BSF adaptation to the subtropical climate. In particular, the high content of lauric acid (melting point: 43.2 °C) could preserve BSF larvae from lipid oxidation and allow them to survive at temperatures above 40 °C . Consistent with other findings, C18:1 c 9 was the main represented MUFA in the larvae, while C18:2 n6 and C18:3 n3 were the main represented PUFA n6 and PUFA n3, respectively.…”

“…[42][43][44] BSF is a subtropical species growing at high temperatures (27-32 ∘ C), and the difficult adaptation to low temperatures was demonstrated by the lowest BSF survival rate at about 16 ∘ C. 45 We can argue that the high SFA presence could be ascribed to BSF adaptation to the subtropical climate. In particular, the high content of lauric acid (melting point: 43.2 ∘ C) could preserve BSF larvae from lipid oxidation and allow them to survive at temperatures above 40 ∘ C. 41 Consistent with other findings, 7,15,32 C18:1 c9 was the main represented MUFA in the larvae, while C18:2 n6 and C18:3 n3 were the main represented PUFA n6 and PUFA n3, respectively. The low quantity of recovered PUFA n3 in the larvae could represent a problem if insect meals are intended to be used for animal feed.…”

“…Being of vegetable origin, all rearing substrates had PUFA as the most abundant FA group. Notwithstanding, as typically observed for Diptera, the BSF larval FA profile was dominated by SFA, mainly C12:0 (which showed the absolute highest values among individual detected FA), C14:0, C16:0 and C18:0 . The high presence of SFA in insects is connected with cold adaptation .…”

“…Notwithstanding, as typically observed for Diptera, the BSF larval FA profile was dominated by SFA, mainly C12:0 (which showed the absolute highest values among individual detected FA), C14:0, C16:0 and C18:0. 32,41 The high presence of SFA in insects is connected with cold adaptation. 42 Indeed, larvae from some species showed a SFA decrease from summer to autumn, while PUFA increased, highlighting a correlation between the change in FA composition and the temperature due to seasonal change.…”

Hermetia illucens meal as fish meal replacement for rainbow trout on farm

“…Therefore it may be assumed that the digestibility of HIM in our study is closer to the values obtained by Lock et al (2015) than to the value obtained by Kroeckel et al (2012). Lock et al (2015) noted that especially C12:0, which is one of the major FA in HIM (Ushakova et al, 2016), remained highly digestible over all HIM inclusion levels. That could, at least partly, be responsible for the significantly improved lipid utilisation in our experiment which may also be a sign of improved energy saving or excess dietary digestible energy but not necessarily for improved lipid utilisation.…”