Solubility of Glycyrrhizin in Supercritical Carbon Dioxide with and without Cosolvent

The solubility of glycyrrhizin in supercritical carbon dioxide (SCCO2) with cosolvent ethanol at the mole fraction of (0, 0.02, and 0.04) was measured, respectively, at pressures of (9 to 21) MPa and temperatures of (308, 318, and 328) K. The results revealed that the glycyrrhizin solubility depended on the pressure, temperature, and cosolvent mole fraction. The glycyrrhizin solubility in pure SCCO2 was well correlated with Chrastil, Bartle, and Mendez-Santiago and Teja models with the average absolute relative deviation (AARD) below 6.82 %. The glycyrrhizin solubility in SCCO2 with cosolvent was correlated by Chrastil modified by Gonzalez (Chrastil-G), and MST modified by Sauseau (MST-S) models with satisfactory AARD below 3.85 %. The results provide fundamental data in designing extraction of glycyrrhizin from the licorice or preparation of its particle using SCCO2 techniques.