Green Solvent-Based Extraction of Lipids and Proteins from Tenebrio molitor: A Sustainable Approach and Cytotoxic Activity

This study compared Tenebrio molitor extracts obtained using various solvents, including ethyl acetate (EtOAc), ethanol (EtOH), isopropanol (IPA) as green solvents, and n-hexane as a conventional extraction method. The investigation involved oil extraction yields, fatty acid composition, total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl scavenging activity, total protein content, and cytotoxicity effects, providing a thorough analysis of the different extraction techniques. Oil extraction yields were significantly higher with green solvents such as EtOAc (25.33±0.01%) and IPA (21.66± 0.02%) compared to n-hexane (18.6±0.02%). Analysis of fatty acid composition revealed high monounsaturated fatty acids levels in all extracts, particularly in EtOAc and EtOH extracts. The polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA) ratio varied among the extracts, with EtOH exhibiting a favourable ratio (PUFA/SFA=1.23). The highest protein yield was achieved through EtOH extraction, with a 0.75±0.01 mg/mL concentration. The TPC analysis showed that EtOH extract had significantly higher TPC (0.70±0.02 mg GAE/g oil) compared to other solvents and exhibited significant antiradical activity (IC50=1.41 mg/mL) compared to conventional n-hexane extract. Cytotoxicity studies demonstrated varying toxicity levels against HepG2 and Huh7 cells, with n-hexane extract exhibiting higher toxicity than other extracts. This study suggests that EtOAc and IPA are promising alternatives for lipid extraction from mealworms. In contrast, EtOH extraction is efficient for protein extraction and maximising polyphenol content, contributing to the potential benefits of mealworm extracts.