Solubility of β-carotene in supercritical CO2 and the effect of entrainers

Solubilities of trans-beta -carotene in supercritical CO2, both pure and modified, were measured at temperatures 313.2, 323.2 and 333.2 K and pressures up to 28 MPa using a one-pass flow apparatus. The solubility data measured in pure CO2 were correlated by the density-based equation proposed by Chrastil, and modelled using the Soave-Redlich-Kwong cubic equation of state. Most of the literature data were in good agreement with our results; smaller discrepancies were ascribed mostly to beta -carotene degradation. While ethanol entrainer increased the solubility of beta -carotene in supercritical CO2 by one order of magnitude, vegetable oil was less efficient. In both cases, the increase in solubility was proportional to square root of entrainer concentration. (C) 2001 Elsevier Science B.V. All rights reserved.