Rapeseed oil that is pressed directly from the seed is typically degummed, neutralized, bleached and then deodorized before being bottled for the shelf. the commercial operations are typically fairly big with capacities upto from 100 to 750 metric tonnes per day.
Not all oil Rapeseed Oil that you find in the supermarket is pressed from the seed, a lot of oil is extracted with Hexane. After removal of the hexane the oil goes through the same steps as the pressed oil.
Degumming: Hydrating the phospolipids using and acid and water wash, tyically removed by a centrifuge.
Neutralizing: Saponification of the FFAs using Sodium Hydroxide and water, again removed by centrifuge.
Bleaching: Addition of bleaching earth under vacuum to remove colour compounds and remove residual gums and soaps from previous steps, Typically removed by Pressure leaf filters.
Deodorizing: Removal of odours and other colour compounds using steam stripping at high temperature and very low vacuum levels.
