Catechin sublimation pressure and solubility in supercritical carbon dioxide

Solubility of (+)-catechin in SC-CO2 was measured at several temperatures (313.15, 323.15, 333.15 and 343.15 K) and pressure in the range of 12–26 MPa using ethanol as the co-solvent (5 mol.%). The experimental data were used for the correlation of density dependent solute solubility parameters. The equations of Chrastil, del Valle and Aguilera, Adachi and Lu, González, and Méndez-Santiago and Tejawere fitted very well for the solubility of (+)-catechin. The rate of mass loss of (+)-catechin showed that its sublimation pressure is very low, an indication of the stability of the compound. Thermogravimetric analysis was used to determine the sublimation pressure.