Abstract
The aim of this study is to investigate the feasibility of supercritical CO2 extraction of glabridin, one of many bioactive components in licorice (Glycyrrhiza glabra). Such operating parameters as the type and amount of co-solvents, temperatures ranging from 40 to 80°C, and pressures ranging from 102 to 500 bar were examined at a constant flow rate of 1 ml/min. The organic solvent extraction with methanol, ethanol and acetone as an extraction solvent was conducted for the comparison to the supercritical CO2 extraction, producing 0.198 wt% of glabridin from licorice. The amount of glabridin within crude extracts was analyzed by high-performance liquid chromatography. The extraction yield of glabridin was of extremely small quantity, when using pure CO2 as an extraction solvent at 340 bar and 80°C. On the other hand, the yield of glabridin increased dramatically as the concentration of acetone in SCCO2 increased up to 25% (v/v). Under a constant temperature, the yield of glabridin increased with increasing pressure from 102 to 500 bar; also, the decrease of temperature from 40 to 80°C made the recovery of glabridin from licorice increased at a constant pressure. In addition, the purity of glabridin in extracts prepared by the supercritical CO2 extraction increased about 2 ∼ 4 times compared with the organic solvent extraction.
