Solubility of some phenolic compounds contained in grape seeds, in supercritical carbon dioxide

The solubility of some natural, low molecular weight phenolic compounds, 3,4-dihydroxy benzoic acid (protocatechuic acid), methyl 3,4,5-trihydroxybenzoate (gallic acid methyl ester or methyl gallate), and 3,4-dihydroxy benzaldehyde (protocatechualdehyde), in supercritical carbon dioxide (SC-CO2) has been determined at pressures from 10 to 50 MPa and temperatures from 313 to 333 K. These phenolic compounds are contained in grape seeds and other natural substrates. The data presented in this work are valuable to know the possibility of separation from their natural matrices by supercritical extraction with carbon dioxide. Data modeling has been carried out by using the Peng–Robinson equation of state (PR-EOS) to describe the behavior of the supercritical fluid (SCF) phase. Two semiempirical density dependent correlations, specifically, the Chrastil model, and a model that assumes a linear correlation between the enhancement factor and the density of the solvent, have also been used for data correlation.