Comparison of Sustainable Lipid and Protein Removal Methods for the Isolation of Insect Chitin from Black Soldier Fly Exoskeleton

Abstract

Black soldier fly (Hermetia illucens), an insect known for feeding on waste biomass and converting it into useful nutrients such as proteins, lipids, and chitin, has been reared on insect farms on a large scale. In this study, chitin was isolated from the exoskeleton of the black soldier fly using different extraction protocols, such as chemical solvents, enzyme-assisted fractionation, and supercritical carbon dioxide extraction. The levels of effectiveness of the recovery of the chitin fraction using different extraction methods were then evaluated by determining the physicochemical properties of the extracted insect chitin using Fourier transform infrared spectroscopy, elemental analysis, and X-ray diffraction. The results show that the use of eco-friendly acids and solvents such as lactic acid, acetic acid, and ethanol as well as bacterial proteases holds promise for the defatting, demineralization, and deproteinization of the exoskeleton to yield good quality chitin, albeit with impurities.

Methanol extract of Black soldier fly (Hermetia illucens) prepupae against Aeromonas and Staphylococcus aureus bacteria in vitro and in silico

“…Chitin is an unbranched long-chain polysaccharide formed from N-acetylglucosamine units linked by −1.4 covalent bonds. Chitin is deacetylated into chitosan, which can be used for various biomedical applications ( Tan et al ., 2021 ). Chitosan, chitin, and their derivatives function as bacteriostatic and bactericidal agents.…”

Chitin Determination in Residual Streams Derived From Insect Production by LC-ECD and LC-MS/MS Methods

“…We assume that the less successful chitin purification from mealworm and cricket exuviae was due to their high lipid content since hydrophobic repulsion was observed throughout the study, thus reducing the accessibility of the acid and alkali solutions to solubilize minerals and proteins (Tan et al, 2021). The outer region of insect exuviae, especially that of mealworm larvae, contains a considerable amount of lipid (Pasquier et al, 2021), which serves as a barrier to protect the insect from abrasion and infection (Roer et al, 2015).…”

“…In contrast, deproteinization is crucial since chitin is compactly bound with cuticular protein in the chitin-protein matrix. This step is challenging since strong conditions are necessary to break the hydrogen bonds between chitin and protein, but prolonged exposure to such a harsh environment also poses a risk of degrading the chitin (Tan et al, 2021). In addition, insect exuviae are diverse, varying in thickness, strength, and elasticity (Andersen, 2010), and so far, there is no standardized extraction method for all types of exuviae.…”

“…For example, the use of alcalase, an endoproteinase enzyme from Bacillus licheniformis, was considered a promising option to solubilize proteins from mealworm exuviae (Jantzen da Silva Lucas et al, 2021). Liquid fermentation by lactic acid-producing Lactobacillus plantarum, protease-producing B. subtilis, and lipase-producing Pseudomonas fluorescens was used to obtain chitin from BSF exuviae (Tan et al, 2021). The possibility of using deep eutectic solvents was also evaluated to remove minerals and proteins from BSF prepupae (Zhou et al, 2019).…”

Update on Chitin and Chitosan from Insects: Sources, Production, Characterization, and Biomedical Applications

“…Microbes can be cultivated in a suitable growth medium containing the insect material, allowing them to release enzymes that break down proteins, lipids, and other organic matter. Yun et al used purified protease from Bacillus licheniformis and Bacillus subtilis for deproteinization and defatting of black soldier fly exoskeletons, respectively [115]. Lin et al used a Bacillus licheniformis A6 strain in the fermentation of spent pupal shells of black soldier flies for chitin extraction [116].…”