Solvent optimization for efficient enzymatic monoacylglycerol production based on a glycerolysis reaction

This study was aimed at screening solvent systems of varying polarities to identify suitable solvents for efficient and practical enzymatic glycerolysis. Several pure solvents and solvent mixtures were screened in a batch reaction system consisting of glycerol, sunflower oil, and Novozymo (R) 435 lipase. Out of 13 solvents tested, tert-butanol and tert-pentanol were the only pure solvents suitable for a fast glycerolysis reaction with an acceptably high formation of MAG. In these systems, MAG contents of 68-82% were achieved within a few hours. Mixtures of tertbutanol/hexane, tert-pentanol/hexane, and tert-butanol/tert-pentanol in varying ratios also gave high MAG contents (58-78%). The tertiary alcohols tert-butanol and tert-pentanol, or mixtures of one of them with hexane, seemed to be the best choice among the solvents tested with respect to reaction efficiency, practical industrial applications, and steric hydroxyl group hindrance, which suppresses the ester formation with FA.