Optimisation of Oil Extraction from Quinoa Seeds with Supercritical Carbon Dioxide with Co-solvents

In the present work supercritical fluid extraction with carbon dioxide was performed to obtain oil from quinoa seeds. The effects of extraction variables - namely pressure, temperature, time, particle size, and co-solvent, on supercritical carbon dioxide extraction are investigated. Total extraction yields and compositions using pure CO2 and CO2 + selected co-solvents are compared. The maximum recovery for quinoa oil is found to be about 89%, and is obtained when extractions are carried out at 25 MPa, 40 degrees C for 80 minutes. A significant effect on the oil recovery is exerted by size reduction of seeds to a particle size <= 0.50 mm and addition of co-solvent to seed in an amount of 20% - methanol/ethanol (1 : 1, w/w). Irrespective of the extraction method and conditions, the fatty acid composition is not substantially changed.