Solubility of two vegetable oils in supercritical CO2

Dynamic method was applied to measure the solubility of oils from seed of Ribes nigrum (blackcurrant) and Vitis vinifera (grape-vine) in supercritical CO2 at pressures up to 29 MPa. The solubility of blackcurrant seed oil, which had been refined prior to the measurement and therefore it contained only triglycerides, was measured at 40–60°C. It was correlated with CO2 density and temperature by adjusting the constants of Adachi–Lu equation. The obtained equation is suitable for predicting the solubility of triglycerides of most vegetable oils. The solubility of grape seed oil, containing large percentage of free fatty acids, mono- and diglycerides, was measured at 40°C. It was twice as large as the solubility of refined blackcurrant seed oil, and it decreased after most of the free fatty acids had been extracted. A simplified stepwise model describing fractionation of the mixture during the solubility measurement was derived and applied to estimate the grape seed oil solubility and its changes.