Lipase-catalyzed esterification of palmarosa oil

The present study was carried out with free lipase to study the conversion of geraniol of palmarosa oil to geranyl acetate using acetic acid as acyl donor. The significant factors such as temperature, enzyme concentration and molar ratio of the reactants were investigated for their effects on the ester conversion. A temperature of 60 degrees C and 50 mu L of the enzyme solution were found to give the best results for 75mM of each substrate. The percentage of esterification estimated by both gas chromatographic analysis (which indicated product formation) and titrimetry (which showed acid consumption, i.e. ester formed) was found to be in good agreement. A mechanism for the reaction was proposed, involving nonlinear inhibition studies (inhibition by acid), validation of the reaction and prediction of the kinetic parameters using polymath. Substrate inhibition with dead end complex of acetic acid was found to represent the kinetic data.