The role of phase behavior in the enzyme catalyzed synthesis of glycerol monolaurate

Abstract

Partial glycerides such as monoacylglycerides (MAGs) are important functional ingredients with various applications in the cosmetics and food industry. Direct synthesis of high purity MAGs is commercially not feasible due to low selectivity and substrate miscibility problems. In this article, a selectivity increase in synthesis towards MAG with the addition of 5 wt% of the amphoteric surfactant cocamidopropyl betaine (CAPB) compared to a solvent free reaction is demonstrated. In comparison to tert-butanol, the addition of CAPB leads to similar MAG contents in the equilibrium state and furthermore CAPB does not need to be removed from the reaction, because it is an approved additive in cosmetic products. Additionally it acts as a solubilizer in the product mixture. By adding 5 wt% of CAPB to the enzymatic glycerolysis of TL, the selectivity towards ML could be increased by 17% compared to the solvent free reaction. Also in the enzymatic esterification of glycerol and lauric acid the addition of 5 wt% CAPB shows an increase in selectivity towards ML up to 9% compared to the solvent free esterification. The major function is a direct influence on the phase behavior of the reaction mixture.