Abstract:

The extraction of ginsenosides from Panax ginseng root using supercritical CO2 reverse microemulsion formed by bis(2-ethylhexyl) sodium sulfosuccinate (AOT), ethanol and water was studied, which was carried out in a 1 L supercritical CO2 extraction device. Single-factor and orthogonal array design methods were applied to optimize the extraction. The effects of 7 parameters on ginsenosides extraction were investigated by the single-factor method. A higher extraction yield of ginsenosides was achieved using ethanol as the cosufactant in comparison with butanol and n-pentanol, with the optimal added amount of 120 ml/ 100 g ginseng. Other 5 parameters such as amount of added water, amount of added AOT, extraction time, temperature and pressure were optimized using the orthogonal array design method. The optimal levels of the 5 parameters for improved ginsenosides extraction were determined as follows: amount of added water 36 ml/ 100 g ginseng, amount of added AOT 0.06 mol/100 g ginseng, extraction time 3 h, extraction temperature 55 ℃ and extraction pressure 30 MPa. An extraction yield of 0.757% was achieved under the optimized conditions. Moreover a dynamic model for ginsenosides yield as a function of extraction time was developed, which was E = 0.870 × (1－ e-0.618t). Compared to supercritical CO2 extraction (SCE), this extraction method yielded more ginsenosides.

Key words: supercritical CO2 reverse microemulsion extraction, supercritical CO2 extraction, ginsenosides