Extraction of Ginsenosides from Ginseng in Supercritical CO2 by Means of Different Enhanced Techniques

The improvement for the yields and mass transfers of polar substances in supercritical CO₂ extraction (SCE) are required due to the characteristics of CO₂. At extraction pressure 25 MPa, extraction temperature 45°C, extraction time 4 h, and CO₂ flow rate 2.0 L/h, total ginsenosides extractions from ginseng in SCE by different enhanced technologies, including modifiers, ultrasound and reverse microemulsions, were presented. The experimental results show that the yield of ginsenosides extracted by ultrasound-enhanced supercritical CO₂ reverse microemulsions extraction (USCRME) is 13.9, 4.9, 3.1, and 1.8 times that by SCE, modifier-enhanced SCE (MSCE), ultrasound-modifer-enhanced SCE (UMSCE), and supercritical CO₂ reverse microemulsions extraction (SCRME), respectively. The total ginsenosides mass fraction of solid extract by USCRM is 4.5 and 2.1 times that by SCE and MSCE, respectively. The extraction rate order of ginsenosides from ginseng by MSCE, UMSCE, SCRME and USCRME is: USCRME > SCRME > UMSCE > MSCE. Ultrasound enhancement for MSCE and SCRME can improve the extraction rate of ginsenosides and does not change total ginsenosides mass fraction of solid extract.