Novel Insights on the Sustainable Wet Mode Fractionation of Black Soldier Fly Larvae (Hermetia illucens) into Lipids, Proteins and Chitin

The black soldier fly larvae (BSFL) is a sustainable ingredient for feed applications, biofuels, composite materials and other biobased products. Processing BSFL to obtain lipid and protein fractions with enhanced functional properties as a suitable replacement for conventional feed ingredients has gained considerable momentum. In this regard, a novel and sustainable wet mode fractionation (WMF) scheme for BSFL was explored. Fresh BSFL were steam blanched and pulped to obtain BSFL juice and juice press cake. Subsequent treatment of BSFL juice employing homogenization or enzyme incubation and further centrifugation resulted in the obtention of four different BSFL fractions (Lipid-LF; Cream-CF; Aqueous-AF; and Solid-SF). Total energy consumption for a batch BSFL (500 g) WMF process was 0.321 kWh. Aqueous and solid fractions were the predominant constituents of BSFL juice. Lauric acid (44.52-49.49%) and linoleic acid (19.12-20.12%) were the primary fatty acids present in BSFL lipids. Lipid hydrolysis was observed in lipids belonging to the solid (free fatty acids > triacylglycerides) and cream fractions. Aqueous fraction proteins (ctrl) displayed superior emulsion stability and foam capacity than other treatments. Juice press cake retained 60% of the total chitin content and the rest, 40%, was found in the solid fraction (ctrl). The material distribution of principal constituents in different fractions of the WMF process and amino acid profile was elucidated. Overall, the versatile WMF process proposed in this study involves simple unit operations to obtain functional ingredients from BSFL, which can be further explored by researchers and industry stakeholders.