Determination of the solubility of extracts from vegetable raw material in pressurized CO2: a pseudo-ternary mixture formed by cellulosic structure+solute+solvent

This paper discusses the application of the dynamic method to measure the solubility in pseudo-ternary systems formed by vegetable raw materials (cellulosic structure+solute) and CO2. For aromatic, medicinal, and spice plants, the soluble portion of the solid is formed of essential oils, oleoresins, pigments, and various substances from several other classes of organic compounds. The experimental data were measured in two independent laboratories, using three experimental set-ups, and three vegetable species: clove buds, eucalyptus, and ginger. The solubility for the system clove buds/CO2 varied from 0.220 to 0.277 kg-extract/kg-CO2 for the isotherm of 288.15 K. The ginger extract solubility varied from 2.01×10 to 7.20×10 kg-extract/kg-CO2 for pressures of 100–300 bar, and temperatures of 298.15–313.15 K. The eucalyptus solubility for the isobar of 66.7 bar varied from 3.95×10 to 4.07×10 kg-extract/kg-CO2. © 2002 Elsevier Science B.V. All rights reserved.