The mechanism of lipase-catalyzed synthesis of food flavoring ethyl butyrate in a solvent-free system

Abstract

Immobilized Lipase-B from Candida antarctica catalyzed the esterification of butyric acid and ethanol under anhydrous solvent-free reaction conditions toward the synthesis of ethyl butyrate, a compound significant as food and perfume flavoring, as well as biofuel. The proton inventory technique was efficiently applied in mixtures of the anhydrous polar solvents ethanol and deuterated ethanol (CH3CH2OD). Subsequently, and by suitable analysis of the experimental data, the aforementioned synthetic procedure seems likely to follow the kinetic mechanism ordered bi-bi involving single substrate dead-end inhibition by ethanol, whereas were estimated values of important parameters. So far is the first experimental evidence that the synthesis of ethyl butyrate, which is catalyzed by immobilized lipase, it follows an entirely different mechanism when it is performed in anhydrous solvent-free system vs. that in anhydrous n-hexane; then it may be constructive for the industrial production of fixed quality of ethyl butyrate.