Optimization of ultrasound‐accelerated synthesis of enzymatic octyl hydroxyphenylpropionate by response surface methodology

The ultrasound-accelerated enzymatic synthesis of octyl hydroxyphenylpropionate (OHPP) from p-hydroxyphenylpropionic acid (HPPA) and octanol was investigated in this study. A commercially available immobilized lipase from Candida antarctica, Novozym® 435, was used as the biocatalyst. A three-level-three-factor Box-Behnken design experiment and response surface methodology were used to evaluate the effects of temperature, reaction time, and enzyme activity on percent yield of OHPP. The results indicated that temperature and enzyme activity significantly affected percent yield, whereas reaction time did not. A model for the synthesis of OHPP was established. Based on a ridge max analysis, the optimum conditions for OHPP synthesis were predicted to use a reaction temperature of 58.8°C, a reaction time of 14.6 h, and an enzyme activity of 410.5 PLU with a yield of 98.5%. A reaction was performed under these optimal conditions, and a yield of 97.5% ± 0.1% was obtained. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010