What is refined oil for cooking? How to make refined cooking oil?

There are two kinds of oil that can get from cooking oil factory. One is crude oil and the other is refined oil. Actually, the oil that get from pressing plant or solvent extraction plant is crude oil, and get from oil refinery plant is refined oil.

Refined oil is also called edible cooking oil, in which the harmful impurities are removed, to meet the national quality standards for food and storage. However, do you know how to make crude oil into refined cooking oil?

The flow chart of making refined cooking oil

Firstly, to remove the colloidal impurities, also called degumming process.

It is using the hydrophilic properties of colloidal impurities. When the hydrophilic properties meets hot water, the colloid impurities in oil will absorb water to expand, condense into particles, and increase the specific gravity. After some time of sedimentation, the colloidal impurities will be separated from the oil. 

Secondly, to remove the free fatty acid(FFA), also called deacidification process or neutralization process.

In chemical refining process, utilize neutralization reaction of lye and the FFA in oil to remove the FFA. During this process, it will produce soapstock, which will be separated from the oil then. At last, by adding the hot water to remove the balance soap which in oil.

In physical refining process, the deacidification process, as well as deodorization process, is finished in deodorizing tower concurrently.

You can process the soap into soap factory or sell these soap stock to other buyers.

Different types cooking oil refining equipment of Henan Doing Company

Thirdly, to remove the coloring matter in the oil, also called decolorization process or bleaching process.

Absorb off some pigment, lecithoid, remnant pesticide and other impurity by adding white clay. And the waste white clay will be filtrated out by leaf/vibrating filter. If you want to get lighter color, you need to add more white clay.

Finally, to remove the bad smell in the oil, also called deodorization process.

Remove off the volatile odoriferous material and free fatty acids in vacuum and high temperature condition. Usually use the steam to take odors away. After that, the final oil will be filtered once again through safety filter.

After these four steps, the oil will meet the requirement of national standard--Not easy to rancidity and deterioration, helpful to storage, do not produce a lot of lampblack when cooking, and maintained grease flavour.