Mechanical and Enzyme Assisted Fractionation Process for a Sustainable Production of Black Soldier Fly (Hermetia illucens) Ingredients

Abstract

This study aimed at effective fractionation of Hermetia illucens into lipid and protein, considering the insects' anatomy. A hybrid approach was developed, separating the exoskeleton by mechanical pressing and fractionating the slurry by sonication and enzymatic treatment. Microscopy showed that the peripheral fat bodies were tightly attached to muscle fibers. Blanching caused protein aggregation and entrapment of fat in the protein matrix, resulting in 25.0% loss in fat extraction, compared to only 3.3% loss for unblanched larvae. After centrifugation of the juice obtained from unblanched larvae a cream layer rich of lipids and proteins, a supernatant with soluble protein, and a pellet including mainly insoluble proteins were obtained. Blanched juice centrifugation formed a lipid fraction, a reduced cream layer, and more pellet. Whereas, sonication hardly affected the fractionation, enzymatic treatment resulted in solubilisation of pellet protein and an increased lipid layer. In conclusion, processing without blanching is very effective to extract more lipids (>80%) from whole larvae in the form of a cream layer, while blanched-enzymatic treatment allows the extraction of lipids in a clear lipid layer (>40%). In both cases, around 50% of protein was recovered in the residue and the other 50% mainly in the pellet after centrifugation.

Mechanical Processing of Hermetia illucens Larvae and Bombyx mori Pupae Produces Oils with Antimicrobial Activity

“…In SP the fat body is mainly perivisceral; this tissue is far more abundant in female pupae, in which fat cells are progressively destroyed to obtain egg maturation [ 38 ]. Recently, other methods were proposed for fat extraction, as mechanical and enzyme-assisted fractionation process, keeping into account the particular distribution of fat in BSFL [ 39 ]. However, in the present study we resorted to mechanical crushing of the dried biomass, which is a quite simple method, already tested for plant seeds, and which requires slight modification of the already existent technologies.…”

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

“…Homogenization of the juice was carried out at 10,000 RPM for 5 min with a high-speed homogenizer (T-18, ULTRA-TURRAX, IKA, Staufen, Germany) and then centrifuged (labelled as "Hg"). The leftover juice was subjected to enzymatic treatment [12], wherein enzyme Alcalase (5% w/w of juice DM) was added to the juice to facilitate hydrolysis for 3 h at 60 • C with gentle agitation. The hydrolysis was stopped by heating the juice-enzyme mixture to 90 • C for 10 min and then centrifuged (labelled as "Et").…”

“…For instance, if industrial-scale feed production necessitates the addition of unique wet formulations, these fractions can be added as such, thereby forgoing any additional requirement of the drying processes. Recently, Azzollini and others [12] proposed a mechanical and enzyme-assisted fractionation process for the production of sustainable BSFL ingredients in which the washed larvae were immersed in hot water (90 • C) and subjected to mechanical separation in order to obtain juice and a chitin-rich fraction (fibrous residue). In that research work, the mechanical separation was accomplished with a slow juicer, and the effect of sonication and enzyme incubation on the juice was elucidated.…”

“…Lipid fraction was the least constituent, making up 3.62 ± 0.07% (Ctrl), 2.85 ± 0.23% (Hg) and 7.79 ± 0.39% (Et) of the total weight. During the proteolysis, the size of the protein aggregates is reduced, facilitating better lipid fractionation [12], which explains the substantial yield increase of lipid fraction in enzymatically treated BSFL juice (Et > Ctrl > Hg). Roughly around 73 to 75% of oil from the starting material of BSFL was lodged in the cream and lipid fractions, combined.…”

“…Improvement in fractionation methods for optimum yield of the three prominent chemical constituents from BSFL (protein, fat and chitin) whilst maintaining their individual functionality and integrity is one of the intriguing challenges in BSFL processing [11]. Within the scope of wet mode fractionation, a mechanical process for sustainable production of BSF ingredients was published in which fresh larvae were directly fractionated [12].…”