FACTORIAL DESIGN FOR THE SYNTHESIS OF ETHYL OLEATE CATALYZED BY NATIVE LIPASE Aspergillus niger.

This work reports the use of the Octave, a free computational software, to optimize the experimental design in the synthesis of ethyl oleate from oleic acid and ethanol catalyzed by a native lipase from Aspergillus niger. The central composite factorial design (CCD) was performed with 2 levels and 3 variables (temperature, mass of native A. niger lipase and oleic acid:ethanol molar ratio) in conjunction with response surface methodology (RSM). The results indicate that variable 1 (oleic acid:ethanol molar ratio; X1) and 2 (mass of A. niger lipase, X2), as well as the interaction between them, are statistically significant. The optimal reaction condition was estimated using ANOVA data and the response surface. The experimental results are consistent with those estimated, and thus, ethyl oleate was obtained with conversion (> 90%) using oleic acid and ethanol in a 1:2 molar ratio, A. niger lipase (8,00 mg) and temperature of 45 °C in 6 hours of reaction.

本研究采用免费计算软件Octave（Octave），对黑曲霉（Aspergillus niger）来源的天然脂肪酶催化油酸与乙醇合成油酸乙酯的实验设计进行优化。实验采用2水平、3变量的中心复合析因设计（Central Composite Factorial Design, CCD），结合响应面法（Response Surface Methodology, RSM），考察的变量包括反应温度、黑曲霉天然脂肪酶投加量以及油酸与乙醇的摩尔比。结果显示，变量1（油酸与乙醇摩尔比，X₁）、变量2（黑曲霉脂肪酶投加量，X₂）及其交互作用均具有统计学显著性。基于方差分析（Analysis of Variance, ANOVA）结果与响应面分析，本研究估算得到最优反应条件。实验结果与估算值吻合度良好：当油酸与乙醇摩尔比为1:2、黑曲霉脂肪酶投加量为8.00 mg、反应温度为45℃、反应时长6 h时，油酸乙酯转化率可达90%以上。