Desorption of onion oil from adsorbent beds loaded with one liter of onion juice by supercritical carbon dioxide at different pressure. temperature, and density was investigated. At constant temperature; when density was increased from 0.69 to 0.86 g/ml at 37 degreesC, the gravimetric yield of onion oil by percentage was increased from 0.0112% to 0.0222%. When density was increased from 0.79 to 0.86 g g/ml at 50 degreesC, the gravimetric yield of onion oil by percentage was increased from 0.0189% to 0.0231%. At constant density of 0.86 g/ml, an increase in temperature from 37 to 50 degreesC increased the gravimetric yield of onion oil by percentage from 0.0222% to 0.0231%. Yield difference was significant (p = 0.05) only for the 0.69-0.86 g/ml density difference. Similar composition onion oil desorbed at the different supercritical carbon dioxide conditions was found by using GC-MS in the analysis of onion oil. (C) 2003 Elsevier Ltd. All rights reserved.