In this context, oxidation refers to chemical reaction of chain fatty acid triglyceride molecules with atmospheric oxygen. Such an effect of oxygen can occur at ambient temperatures or at lower temperatures, for example, during normal storage of oils or prepared foods. It can also occur at higher temperatures, for example, during cooking or frying.
In order to protect oil and improve its stability it is necessary to prevent exposure to oxygen from the very beginning - from the moment of oil production. Effective alternative is the use of nitrogen in the food industry, the importance of this method increases due to the global trend of replacing physical and chemical techniques for the conservation.
Nitrogen is chemically inert gas that does not directly interact with the product. Nitrogen is used to displace air and thus oxygen and water vapor, which helps prevent oxidation. Oxygen is replaced with nitrogen using two different methods: sparging, which removes dissolved oxygen, and filling, which guarantees the absence of oxygen in the free space.
Using each of these methods obviously depends on the product type and stage of processing. For example, filling with nitrogen is useful for the collection tanks, which are used for intermediate fractions of oils, as well as tanks for storing raw oil and ready oil.
Also, there is another method, which is widely used in the production of fats and mayonnaise - so-called beating. The main purpose of this method is to change the product consistence. This method is mainly used for fats used in bakery products, and helps to obtain the desired consistence using an inert gas and to prevent exposure to air.