Supercritical carbon dioxide extraction of trans-anethole from Foeniculum vulgare (fennel) seeds: Optimization of operating conditions through response surface methodology and genetic algorithm

The extraction of trans-anethole from fennel seeds is assessed by supercritical CO2 together with ethanol as the modifier. The experiments and modeling are designed through response surface methodology (RSM). The fennel extract is analyzed by gas chromatography-flame ionization detector (GC-FID). RSM design and genetic algorithm (GA) are applied to optimize the SFE variables and trans-anethole recovery. The maximum trans-anethole recovery (56.38 w/w % and 55.50 w/w %) is obtained at optimal operating conditions at 21.3 and 21.55 MPa, 60.2 and 55.59 degrees C, 103 and 96.38 min and 1.74 and 1.49 ml/min of CO2 through RSM and GA, respectively. According to response surface analysis, R-2 and modified R-2 of the model are 96.64% and 93.71%, respectively. The accuracy of modeling optimal trans-anethole recovery is validated through triplicate experiments providing the average extraction recovery of 55.3 +/- 1.5% and 54.5 +/- 1.2% for RSM and GA, respectively.