Kinetics and optimization of lipase-catalyzed synthesis of rose fragrance 2-phenylethyl acetate through transesterification

Lipase from Candida rugosa was immobilized on a polyvinylidene fluoride membrane for synthesis of rose flavor ester, 2-phenylethyl acetate. Response surface methodology (RSM) was employed for kinetic modeling of process and prediction the yield. The RSM was used in practice for determining the kinetic models by fitting the initial rate dates based on the equations of ping-pong bi-bi and order bi-bi model. The maximum reaction rate and kinetic constants were matched with the order bi-bi model. The specificity constant of the immobilized lipase was 10-folds higher than the free form indicated the enzyme-substrate affinity, and catalytic ability was enhanced after immobilization. Moreover, the effects of reaction parameters on the yield were evaluated by RSM using a Box-Behnken experimental design. Based on a ridge max analysis, the maximum conversion was 95.33 ± 2.57% at 38.78 h, 35.85 °C, and substrate mole ratio of 3.65:1. Furthermore, the order bi-bi kinetic model was simulated successfully in a batch reaction. A good prediction existed between the RSM results and integrated equation was found.