The main component of fats is fatty acid glyceride, also contains a small amount of free fatty acids and other impurities. After refining the oil, remove harmful ingredients and retain beneficial ingredients. There are usually three steps in the refining method: neutralization, decolorization, and deodorization.
Neutralization generally uses sodium hydroxide to remove free fatty acids, and also has the function of removing proteins and gums, and reduces other impurities. If you want to change the color of the oil to monochrome, you need to do further processing. Usually, activated clay and powdered activated carbon are used in combination to achieve the effect of decolorization, deodorization and deodorization.
The decolorization of edible oil is also important for the selection of activated carbon. The activated carbon products produced by different activation methods are also different. It is suitable for the decolorization of different oils. It is generally better to conduct experiments before usage. The pH of activated carbon is also very important, controlled between 5-8, too alkaline or too acidic will cause undesirable changes in edible oil.