1. Neutralization
Neutralization phase will eliminate a large amount of free fatty acids contained in oil. This will increase the smoke point, flash point and fire point. So, when margarine used for frying will not be easily oxidized to form acrolelin undesirable because it can cause itching in the throat.

The reaction occurs (Glycerol Oxidation Reaction):
Glliserol -------> acrolein

Free fatty acid levels left after the neutralization process is only about 0.13 percent. At this stage also will be formed soap sparingly soluble in oil.

2. Bleaching
Bleaching is the process of removing dye that is not preferred in the oil.
  • Oil loss due to this process is more or less at 0.2 to 0.5 percent by weight of the oil produced after the bleaching process.
  • Levels of soap at this stage of neutralization will be reduced to 50-10 ppm.
  • Levels of metals from the neutralization process will be reduced until 0001 - 0.1 percent.
  • Adsorbent will eliminate unwanted odors and reduce the amount of peroxide that will improve the quality of oil.
3. Hydrogenation
Hydrogenation will result in the loss of the double bond, which would make the oil or fat is resistant to oxidation and also more plastic. The process of hydrogenation will convert linolenic acid to linoleic acid, and linoleic acid converted to oleic acid. Free fatty acid levels will drop to about 0.1-0.3 percent.
linolenic ---> linoleic ---> Oleic

4. Deodorization
After Deodorization, free fatty acids and peroxide will evaporate and only remain approximately 0.015 to 0.03%. The fraction that does not reacting consisting of chlorophyll, vitamin E, hydrocarbons (mainly squalene and sterols) will be reduced by approximately 60% of the total fraction. Damage to oil that has undergone a process Deodorization can be caused by microbial oxidation and hydrolysis of metal ions such as Cu, Mg, Fe, Zn which was the catalyst in the oil oxidation process. The metal can make a complex compounds with the results of fatty acid oxidation and turns into free radicals.

5. Emulsification
Vitamin A and D will increase in the oil. Besides the oil will be shaped to form an emulsion with water and margarine. Some additional ingredients such as salt, anti-oxidants and sodium benzoate will also emulsificated in margarine in the form of a liquid phase emulsifier.

6. Packaging
Margarine packaging will reduce the possibility of fungal and bacterial contamination.

Read More : Manufacturing Process of Margarine from Rubber Seed Oil