If your peanut oil is squeezed out, it can reach the national standard without refining. If you want to obtain peanut oil with higher quality and standard, you can do further freezing filtration, that is, remove phospholipids, protein and other impurities in peanut oil by crystallization filtration, so that you can obtain peanut oil with higher value.
The extracted peanut oil must be refined by peanut oil to remove all impurities of peanut oil, including colloid impurities, free fatty acids, pigments, odor substances and other impurities. All the components of refined peanut oil meet the national standards and can be sold in the market.
The refining process of peanut oil is divided into degumming, deacidification, decoloration and deodorization due to the different impurities removed. Each step can remove different impurities.
Degumming is to introduce hot water into peanut oil to coagulate colloidal soluble impurities, and then to settle and separate them.
There are two ways to deacidify. One is chemical deacidification. Chemical deacidification process is to add lye to peanut oil, neutralize peanut oil with free fatty acid, and discharge by-product soapstock. The other is physical deacidification, which is carried out in deodorization tower. First, steam is introduced into the deodorizing tower to remove free fatty acids.
Decolorization is to remove the pigment from peanut oil by the adsorption of clay, and at the same time, it can also take away some other impurities.
Deodorization is also carried out in the deodorizing tower. Steam is introduced into the deodorizing tower, and the odorous substances are separated due to the different volatilities of steam and odorous substances.
The refining process of peanut oil can be completed after deodorization.