In this work, extraction of sesame oil from sesame seeds using supercritical CO2 was carried out. The effect of operating parameters such as pressure, temperature, and supercritical CO2 flow rate and particle size on extraction yield were investigated. An increase in the pressure and the supercritical CO2 flow rate improved the extraction yield and also shortened the extraction time. The extraction yield increased as the particle size decreased depending on decreasing intraparticle diffusion resistance. The maximum extraction yield obtained was about 85% (relative to Soxhlet extraction by hexane) at 50 degrees C, 350 bar, 2 mL CO2/Min, 300-600 mu m of particle size. Some extraction curves were modeled with two mathematical approaches as shrinking core model and broken and intact core model. The evaluation of model parameters showed that shrinking core model, however, is better than broken and intact cell model. (C) 2009 Elsevier Ltd. All rights reserved.