The main purpose of edible oil refining is to make the oil suitable for human consumption. This involves making the oil flavorless, odorless, change in color, change in the crystal habit, rearrangement of their molecular structure and to make the extracted or mechanically pressed oil suitable as per our requirements.
Another reason for the vegetable oil refining is to obtain triglycerides with high yield and purity, and to produce value added co-products from processing stages like Degumming, Neutralization, Bleaching, Dewaxing/Winterization and Deodorization.
Edible oil refinery plant main steps:
- Crude edible oil degumming: In this step gums in crude corn germ oil are removed by hydration with the help of phosphoric acid.
- Deacidification ( neutralization): In this step free fatty acids are neutralized by using sodium hydroxide and convert them into soap. Additional impurities are also removed by adsorption on soap.
- Decolorization : During decolorization, unwanted pigments are adsorbed physically and oil will become much clearer.
- Deodorization: Deodorization is used to remove unacceptable odors by steam distillation, the odoriferous compound are stripped off with the help of live injected steam into heated oil under high vacuum pressure.
- Dewaxing (necessary for cold areas)