Process Improvement on the Lipase-Catalyzed Synthesis of Oleyl Palmitate, a Wax Ester via Response Surface Methodology （RSM）

High performance enzymatic synthesis of oleyl palmitate, a wax ester was carried out by lipase-catalyzed esterification of palmitic acid and oleyl alcohol. Response surface methodology （RSM） based on 5-level, 3-variable of centre composite rotatable design （CCRD） was used to evaluate the interactive effects of synthesis, of temperature （40-60 ℃）; amount of enzyme （0.1-0.4 g） and substrate molar ratio of oleyl alcohol to palmitic acid （1：1-4：1） on the percentage yield of wax ester. All reactions were fixed at 1 hour of reaction time. The optimum condition obtained from RSM for the reactions were temperature of 57.9 ℃, enzyme amount of 0.26 g and molar ratio of substrates of 2.92. The actual experimental yield was 91.2% under the optimum condition, which compared well with the maximum predicted value of 92.0%. Comparison of predicted and experimental values reveal good correspondence between them, implying that empirical models derived from RSM can be used to adequately describe the relationship between the factors and response in the synthesis of oleyl palmitate.