Solubility of β-carotene and co-solutes in supercritical carbon dioxide for ternary systems: Experimental data and correlation

Ternary carbon dioxide - beta-carotene - co-solute systems have been studied with the aim of examining the equilibrium solubility of beta-carotene and co-solutes in carbon dioxide at supercritical conditions. Co-solutes were alpha-tocopherol, palmitic acid, and capsaicin. Experiments were performed by using a semi-continuous type apparatus from 10 to 36 MPa at 308.15 and 328.15 K. Binary beta-carotene and co-solute mixture was initially fed to the cell at the same mass ratio (1:1). It was found that beta-carotene shows the lowest solubility values for any system at 308.15 K. On the other hand, the co-solute that exhibits the highest solubility was palmitic acid at 328.15 K. Experimental data were modelled using the semi-empirical equations proposed by Chrastil, Kumar and Johnston, and Mendez-Santiago and Teja. Selectivity of carbon dioxide for each co-solute in the presence of beta-carotene was also evaluated.