The application of face-centered central composite design for the optimization of patchouli oil extraction from pogostemon cablin benth dried leaves using microwave hydrodistillation method

The extraction of essential oils from patchouli leaves (Pogostemon cablin Benth) using microwave hydrodistillation (MHD) has been described by many authors as an environmentally friendly process (green technique). This may be attributed to the fact that the method uses low energy and provides fast extraction when compared to other conventional (HD) methods. The optimum conditions for patchouli oil extraction using MHD method are determined with the use of a response surface methodology (RSM). In this study, face-centered central composite design (FCCCD), a type of RSM, is employed to evaluate the effect of the microwave power (A: 300 W, 450 W and 600 W), the feed to solvent ratio (B: 0.2, 0.3 and 0.4 g mL^-1), and the extraction time (C: 60 min, 120 min and 180 min) on the extraction of patchouli oil. The results of the experiment show that optimum conditions referring to the microwave power of 460.823 W, F/S ratio of 0.321 g/mL, and extraction time of 161.15 min are required to obtain a maximum yield of 6.01 % of patchouli oil.