The soya crude oil contains certain soluble and insoluble impurities that needs to be removed like phosphatides, free fatty acid, sediments, moisture, volatile matter, color etc.

The purpose of refining is to eliminate these impurities to make the edible grade oil. The insoluble impurities are removed with filtration while the soluble impurities are removed with different processes like degumming and neutralization, washing, vacuum drying, bleaching and  de-odorisation etc.