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.