Supercritical CO2 extraction of flaxseed

Extraction of flaxseed oil was performed with supercritical carbon dioxide (SC-CO2). To investigate the effects of pressure and temperature on the solubility of oil and oil yield, three isobaric (21, 35, and 55 MPa) and two isothermal (50 and 70degreesC) extraction conditions were selected. Although the maximal solubility of flaxseed oil, 11.3 mg oil/g CO2, was obtained at 70degreesC/55 MPa, the oil yield obtained after 3 h of extraction at this condition was only 25% (g oil/g seed x 100), which represented 66% of the total available oil of the flaxseed. Lipid composition and FFA and tocol (tocopherol and tocotrienol) contents of the oils obtained by both SC-CO2 and petroleum ether extraction were determined. The alpha-linolenic acid content of the SC-CO2-extracted oil was higher than that obtained by solvent extraction.