Parsley seed oil extraction with supercritical carbon dioxide at pressures of 10 and 15 MPa, temperatures of 308 and 318 K, flow rates of 0.7, 1.1 and 2 kg/h and mean particle sizes of 293 and 495 mum was investigated in a bench-scale apparatus. For the correlation of the experimental data, a mass balance model coupled with various assumptions-including those of the Lack's plug flow model-was employed. Comparison of the results demonstrated that best fit is obtained when the model takes into account the equilibrium as well as the mass transfer phenomena, that control the extraction process. (C) 2003 Elsevier B.V. All rights reserved.