Because nitrogen is inert at room temperature, it is not easy to breed bacteria, so it is widely used in the preservation and storage of drinks, fruits, vegetables, cakes, tea, Chinese herbal medicine, pasta and other food. It can keep its original color, aroma and taste, and its storage quality is obviously better than that of mechanical refrigeration.

1. Food packaging

In the packaging of fried food, puffed food, baked food, fresh cut agricultural products, special cheese and fresh meat, nitrogen filled packaging is rapidly replacing the traditional vacuum packaging. Nitrogen filled packaging can better maintain the taste, taste and nutrition of food, and its application field is expected to further develop.

Food spoilage is mainly due to the oxygen involved in the oxidation reaction, promoting the reproduction of microorganisms and bacteria, leading to food spoilage. As a kind of asphyxiating inert substance, N2 can suffocate and inhibit the bacterial reproduction in food. The purpose of using N2 is to eliminate O2 and slow down the oxidation and respiration of food. The solubility of N2 in water and oil is very small, and the adsorption capacity of N2 on food is relatively small. Therefore, it can be used as a good food preservation gas.

In addition, nitrogen filled packaging can also play a good role in protecting the internal shape of food; it can prevent crispy and fragile food from being crushed; it can prevent packaged food from being squeezed and bonded together due to the imbalance of internal and external pressure, so that its texture becomes hard; even if the shape becomes hard, it can also keep the appearance of the packaging body surface for irregular food, and reduce the packaging material due to surface folding Food spoilage.

2. Beverage mixing

Dissolved oxygen in liquids and oils precipitates them. The oxygen in these liquids deteriorates them and shortens their life. A method called mixing (through a sprayer to compress liquid with compressed gas) is used to pass gaseous nitrogen into the liquid during processing. Nitrogen bubbles are discharged into oxygen to prevent oxidation, decay and discoloration of carbon free beverages (juice, tea and milk) and edible oils (peanuts, olives, sunflowers and rapeseed oil).

3. Nitrogen expansion

Other types of food need to be filled with gas to increase volume. Using nitrogenous "fluffy" cooking oils, mayonnaise, barreled margarine or peanut oil products can increase their volume and expansion power, thereby extending their life.

Therefore, the air separation plant still has many advantages.