Study on the Supercritical Carbon Dioxide Extraction of Onion Oil

Supercritical carbon dioxide extraction on a pilot-scale was applied to produce onion oil from freeze-dried onion powders.The aim was to obtain the optimal conditions for extracting onion oil.A polynomial model was established on the data.The statistical analysis showed that the extracting pressure,temperature and time have significant influence on the yield of onion oil.The optimal parameters were that extracting pressure,28 MPa;extracting temperature,42 ℃;extracting time,216 min.At this condition,the yield of onion oil could be 0.483%.