The effects of Gac oil extraction conditions including microwave power, microwave time, steaming time and hydraulic pressure on extraction efficiency (EE), and beta-carotene and lycopene contents were studied. It was found that the EE, and beta-carotene and lycopene contents could be enhanced by suitable extraction conditions. Microwave drying was found to be better than air drying for pretreatment. Moisture content after drying and steaming between 8% and 11% (wt/wt) were best for pressing. Results showed that the most suitable conditions for Gac oil extraction from 900 g samples were microwave power of 630 W. microwave time of 65 min, steaming time of 20 min and hydraulic pressure of 170 kg/cm(2). Under these conditions, the highest EE of 93% was achieved while Gac oil contained the highest content of beta-carotene and lycopene at 140 and 414 mg/100 mL, respectively. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.