Enhanced synthesis of feruloylated acylglycerols by the lipase-catalyzed transesterification of glyceryl monoferulate with different acyl donors using ionic liquids as reaction solvents

Abstract

Feruloylated acylglycerols (FAG) can be used as antioxidants and UV absorbing ingredients in food and cosmetics. In this work, FAG was prepared by the lipase-catalyzed transesterification of glyceryl monoferulate (GMF) with different acyl donors using ionic liquids (ILs) as reaction solvents. The effect of different imidazolium ILs (BF4−, PF6− and TF2N−) and acyl donors (monoacylglycerols and diacylglycerols) on the transesterification and lipase selectivity for FAG formation were compared. The effect of reaction parameters (temperature, enzyme concentration, substrates ratio and time) on the reaction were also studied. The results showed that FAG preparation can be enhanced using monoolein (MO) and distearin (DS) as acyl donors. High transesterification activity and excellent lipase selectivity for lipophilic FAG formation were achieved using [C18MIM]PF6 as reaction solvent. The activation energy to form the lipophilic FAG by transesterification using MO as an acyl donor was 37.2 kJ/mol, which was lower than that of DS (92.9 kJ/mol). The activation energy to form the hydrophilic glyceryl diferulate by the esterification of GMF with feruloyl formed by the hydrolysis of another GMF (21.5 kJ/mol) using MO as an acyl donor was lower than that of DS (61.9 kJ/mol).