Circular organic economy through insect biorefineries: Utilisation of organic compounds from Hermetia Illucens larvae for biomedical applications

Abstract

Food waste is a critical global issue contributing significantly to methane emissions. Addressing this requires innovative solutions, such as adopting a circular economy approach to valorise food waste. This thesis evaluates using BSFL for the bioconversion and valorisation of organic waste, focusing on extracting valuable products like BSFL oil and chitin using SC-CO2. The study investigates potential biomedical applications of these products, assessing the cytotoxicity of BSFL lipid and synthesizing a chitosan-based hydrogel for biomedicine.

SC-CO2 is compared against traditional solvent extraction, with a response surface modelling approach used to optimize extraction conditions by examining the effects of temperature, pressure, and extraction time on oil recovery, fatty acid composition, and the ratio of saturated fatty acids (SFA). SC-CO2 extraction outperforms conventional methods, achieving a 35.6% oil recovery, 5.6% higher than solvent extraction, and improving SFA concentration ratios. Optimal conditions yield a maximum oil recovery of 30.1%, lauric acid content of 52.0 g/100g, and minimum SFA ratio of 5.0.

BSFL lipids are rich in lauric acid, which is beneficial for cell migration and non-cytotoxic. Chitosan from BSFL is also a valuable biopolymer, and chitosan-based hydrogels show promise for biomedical applications. Hydrogels with higher gelatin content have a 288% swelling ratio and degrade significantly, while those with more chitosan degrade slower and have a 137% swelling ratio.

This study shows that SC-CO2 extraction is a promising method for converting low-value waste into high-value biomedical resources. The SC-CO2 can be scaled for industrial use, enhancing the circular economy performance of organic waste and creating new markets for BSFL products. Integrating BSFL into waste management contributes to a more sustainable and circular future, offering a model for circular economies globally to revolutionize food waste management.