Kinetics of oil extraction from canola (rapeseed)

Abstract The extraction of oil from canola (rapeseed) using hexane as a solvent can be described by a two stage washing/diffusion model. Oil which is at the surface of the seed as a result of pressing or cooking is removed rapidly at the beginning of the extraction process by simple washing by the solvent. This is followed by a slow extraction of the oil from the seed by a diffusional process. This latter process appears to be controlled by two mechanisms: slow, unhindered diffusion of oil held in the ruptured cells in the seed; and very slow, hindered diffusion of oil held within unruptured cells in the seed. To evaluate this model, rapeseed was extracted with commercial hexane in a simple bench scale batch extractor and the effects of variables such as particle thickness, temperature, cooking, degree of agitation, and solvent‐to‐seed ratio were studied.