Optimization of essential oil extraction from Launaea acanthodes Boiss: Utilization of supercritical carbon dioxide and cosolvent

Abstract

This research focuses on extraction of medicinal plant Launaea acanthodes (L. acanthodes) by using supercritical carbon dioxide (SCCO2) and hydro-distillation (HD) methods. The influence of pressure, temperature, flow rate and volume of co-solvent on the extraction yield of L. acanthodes was investigated by response surface methodology (RSM) and artificial neural network (ANN). The error values of RSM (R2=0.9871, MSE=0.000016 and AARD=2.395) and ANN (R2=0.9968, MSE=0.0000057 and AARD=1.301) were calculated. The results exhibited that both models have the ability to predict the experimental data, but ANN was more reliable than the RSM. The maximum extraction yield was estimated by RSM to be 1.0250% under the operational conditions of pressure 240bar, temperature 328K, flow rate 4.06g/min and co-solvent 663μl; whereas the optimum extraction yield estimated by hybrid ANN-GA method was 1.0238% applying the operational conditions of pressure 240bar, temperature 328K, flow rate 3.98g/min and co-solvent 650μl. The maximum yield (1.0238%) obtained at the optimal conditions was more than that achieved by hydro-distillation method (0.7530%). The extracted components obtained from both methods were analyzed by GC/MS and GC-FID. The main compounds found in the extracts were γ-Phenylbutyric acid (9.29, 9.19%), Geranyl acetone (7.67, 7.87%), n-Hexadecane (7.34, 6.26%), (Z)-3-Hexen-1-yl-benzoate (7.10, 6.91%), n-Dodecanal (5.87, 6.56%), (2Z,6E)-Farnesol (5.65, 4.34%) and Benzoic acid n-hexyl ester (5.13, 4.51%) and β-Ionone (4.55, 4.58%) for SCCO2 and HD methods, respectively. To the best of our knowledge, this is the first report on the extraction of essential oil from L. acanthodes.