Journal of the Science of Food and Agriculture 2012-08-15

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

Chia-Hung Kuo, Shu-Hua Chiang, Hen-Yi Ju, Yu-Min Chen, Ming-Yuan Liao, Yung-Chuan Liu, Chwen-Jen Shieh

Index: J. Sci. Food Agric. 92(10) , 2141-7, (2012)

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Abstract

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 antarcticResponse 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.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.