Introduction To Neutralizing Technology
This is the first process of refinery. It is also called the alkali neutralizing process. In every cooking oil there will be some proportion of free fatty acids – ffa that increase the rancidity in the oil and it is harmful to the health. The ffa percentage is found different in different oils at different stage.
In some fresh oils of fresh oilseeds like groundnut oil, sesame oil, sunflower oil the ffa percentage will found very less. Hence it can be also used directly without refined for eating purpose. While cottonseed oil, palm oil, soybean oil, corn oil, coconut oil is having a high ffa hence it is advisable to use these oils after refining.
But in some countries these oils are also used without refining as per people’s choice. The refined oil can be stored for long time. Any crude oil will be heated in the neutralizer with continues and required type of stirring at required temperature by adding the required quantity of caustic soda (sodium hydroxide – NAOH).
During the process, ffa will be separated in form of soap stock, which can be used in the preparation of laundry soap. To remove the alkali particles, the water wash to the neutralized oil is given. This operation is done in the same vessel of neutralizer.