Applicability of MTBE-based lipid extraction methods assisted by microwave in food analysis. Statistical comparison and greenness evaluation with Soxhlet and Matyash

This research investigates the applicability of a microwave-assisted extraction (MAE) methodology using methyl-tert-butyl ether (MTBE) as a one-step organic solvent extraction or in mixture with methanol and water compared to conventional extractions for lipid analysis in food samples. MAE methods were compared in terms of extraction yields and fatty acid (FA) composition to Soxhlet (using n-hexane, MTBE, and diethyl ether) and Matyash (MTBE/CH3OH/H2O, 10/3/2.5, v/v/v), considered gold-standard methodologies for lipid extraction. FAs, derivatized into methyl esters (MEs), were analyzed through a gas chromatography-flame ionization detector. One-way ANOVA and post-hoc Tukey tests were used to identify statistical differences in yields and FAMEs composition, resulting in <10 % with a p < 0.05. Methods using MTBE/CH3OH/H2O showed higher yields but also higher FAMEs variability compared to one-step solvent extraction methods. The extraction techniques showed comparable performance in terms of FAMEs composition. The greenness of the extractions were also evaluated using the AGREEprep metric.