Carbon dioxide extraction of canola seed: Oil solubility and effect of seed treatment

Abstract

Abstract The extraction of oil from fixed beds of canola seed ( Brassica napus ) was studied using carbon dioxide at temperatures and pressures ranging from 25 to 90°C and 10 to 36 MPa, respectively. The oil solubility in CO 2 was found to be strongly dependent on CO 2 pressure and weakly dependent on the system temperature. The highest observed oil solubility was 11 mg/g CO 2 and occurred at 36 MPa and 55°C. The manner in which different methods of seed pretreatment (flaking, cooking, pressure rupturing, chopping and crushing) affected the extraction process also was studied. The total amount of oil recovered from the seeds by CO 2 extraction was found to be strongly dependent on the pretreatment. No measurable quantity of oil chould be recovered from whole, intact seeds. The amount of oil extractable from flaked and cooked seeds was comparable to that recoverable by conventional hexane extraction.