Taking canola oil as an example– pressed canola oil is too impure and has a nasty stink to it, so in order to be used in food it has to be refined. This refini

Taking canola oil as an example– pressed canola oil is too impure and has a nasty stink to it, so in order to be used in food it has to be refined. This refining usually involves: Extracting it using hexane, degumming with maleic anhydride and/or citric acid, neutralizing with sodium hydroxide, bleaching with clay, activated charcoal, and/or hydrogen peroxide. Then dewaxed with some combination of methyl ethyl ketone, toluene, dipropylene glycol and ethylene glycol, and finally deoderized via steam distillation.