Compositional analysis of black soldier fly (Hermetia illucens L.) larvae and adults

Abstract

The lipid, protein, chitin, and mineral composition of black soldier fly larvae and adults reared on spent brewer’s grain and Gainesville diet were determined via a suite of analytical techniques. The lipid profile of larvae was dominated by triacylglycerol-bound (83.3 wt.%) saturated, unsaturated, and methyl-branched fatty acids. Cyclopropane and oxo fatty acids were identified as minor constituents (up to ~0.7 wt.%). Adults possessed a similar fatty acid profile to larvae, with free fatty acids (54 wt.%) representing the dominant species. Unsaponifiable lipids consisted of trace alcohols and sterols in addition to n- and methyl-branched alkanes (~4.6 wt.%). Larvae and adult protein isolates were dominated by glutelins followed by prolamins, globulins, and albumins. These proteins were bound, and the typical isolate preparation procedure yielded very low recoveries (~1.4-7.7 wt.%). The surface hydrophobicity, oiland water-holding capacity of the protein isolates were determined to highlight the functionality of insect proteins. The information presented herein will serve to further the utilisation of the black soldier fly larvae and adults as food, food ingredients, and feed.