Lipid analyses of oil-bearing biomass using a thermally induced derivatization method

Abstract

This study assessed the efficacy of a commercial fatty acid (FA) methylation kit for analyzing insect/microalgal biomass lipids by comparing it to a thermally induced derivatization method, which is known for its high conversion yield and impurity resistance and serves as a benchmark for evaluating kit performance, as a comparative standard. In insect lipid analysis, kit-based derivatization demonstrated a lower yield of FA methyl esters (FAMEs) than that of the thermally induced method, which is attributable to inherent technical limitations (vulnerability to impurities). This yield discrepancy was further highlighted in microalgal lipid analyses. The efficiency of FA derivatization using the kit-based method was contingent on the lipid structure, as evidenced by the diminished conversion yields for wax esters in Euglena gracilis. Furthermore, for Chlamydomonas reinhardtii, the lower FAME yield observed with kit-based derivatization suggested potential inadequacies in lipid extraction, particularly in the presence of rigid cellular structures such as cell walls. This reduced interaction between lipids and methanol could lead to diminished FAME conversion yields. These findings highlight the notable influence of the biomass type and lipid structure on the efficiency of kit-based derivatization, potentially yielding suboptimal results in lipid analysis.