A mathematical model of a supercritical fluid extraction process was developed and applied to a case study involving the isoflavone extraction from soybean meal using supercritical carbon dioxide with aqueous methanol as a cosolvent. A shrinking core model was applied after considering various mass transfer mechanisms. Model parameters, i.e. solubility (C-sat), film mass transfer coefficient (k(f)), effective diffusivity (D-e), and axial dispersion coefficient (D-L were evaluated using available correlations. The proposed model satisfactorily described the extraction yield without using any adjustable parameters (AARD= 6.54%). The effects of operating parameters, i.e. pressure, temperature, carbon dioxide flow rate, particle size, and cosolvent concentration, on the transport properties and the extraction yield were investigated. Furthermore, a sensitivity analysis of each model parameter was conducted to determine its influence on the prediction of the extracted yield. The model was found to be most sensitive to the film mass transfer coefficient and the solubility. (C) 2011 Elsevier B.V. All rights reserved.