Enzymatic synthesis of rose aromatic ester (2-phenylethyl acetate) by lipase

BACKGROUND: 2‐Phenylethyl acetate (2‐PEAc) is a highly valued natural volatile ester with a rose‐like odour that is widely used to add scent or flavour to cosmetics, soaps, foods and drinks. In this study, 2‐PEAc was synthesised enzymatically by transesterification of vinyl acetate with 2‐phenethyl alcohol catalysed by immobilised lipase (Novozym^® 435) from Candida antarctic RESULTS: Response surface methodology and a three‐level/three‐factor Box–Behnken design were used to evaluate the effects of time, temperature and enzyme amount on the molar conversion % of 2‐PEAc. The results showed that temperature was the most important variable. Based on the ridge max analysis results, optimum enzymatic synthesis conditions were predicted as a reaction time of 79 min, a temperature of 57.8 °C and an enzyme amount of 122.5 mg. The predicted and experimental yields were 86.4 and 85.4% respectively. CONCLUSION: Three immobilised lipases were screened and 15 reaction conditions were tested in order to find the combination for maximum yield. The optimisation of 2‐PEAc synthesis catalysed by Novozym^® 435 was successfully developed. The kinetic study of this transesterification reaction showed that it followed an ordered ping‐pong bi‐bi mechanism without any inhibition by reactants. Copyright © 2012 Society of Chemical Industry