Nitrites in food are mainly from two aspects: the first one is food additive and another source is the nitrogen fertilizer. The attractive color of meat products is formed by nitrite. Nitrite can have reactions with hemoglobin in the meat. It forms pink color that can increase appetite and flavor of the meat. In addition to become color agent for meat, the nitrite also plays a preservative role. It is mainly for the sausage, ham, luncheon meat and other foods. Chinese provisions require that nitrate usage in meat and meat canned shall not exceed 500mg/kg.The adding amount of nitrite shall not exceed 150mg/kg.

On the one hand, nitrite is toxic and can cause cancer. It can be used in food preservation, and extensive use of nitrite in food. Therefore, every day will intake of nitrite, there is the possibility of attacks by nitrosamines, there is the risk of cancer. Fortunately, the intake of nitrite in the body metabolism is faster, generally does not appear to chronic poisoning. Nitrite toxicity, if the excessive intake of nitrite and hemoglobin in the iron reaction, the blood loses the ability to transport oxygen, resulting in the poisoning of the body organs from lack of oxygen, severe cases can The cause of death in patients, such a case there have been many incidents. The experts tell us in this regard, the rational use is safe and will not cause harm to humans.

Inhibit the formation of nitrite, especially the leftovers in the nitrate into nitrite in the role of microorganisms. So, it was suggested not to eat overnight food, the key is to prevent nitrate into nitrite. Nitrite in foods can not be avoided, because much food added artificially food additives, therefore, inhibit the formation of nitrosamines in food or blocking carcinogenic nitrosamines. The pharmaceutical raw materials vitamin C is very effective in the inhibition of precursor. In addition, vitamin C is an antioxidant, can block the formation of mutagens in the extracellular tumor suppression effect. Intake of fresh fruit and vegetables all contain vitamin C such as kiwi fruit, oranges, fresh dates, and hawthorn. A variety of vegetables are also blocking nitrosamine formation.

Vitamin A block of N-nitrosamines carcinogenic effects and the role of inhibition of tumor cell proliferation and growth. Therefore, the choice of vitamin A or containing β-carotene-rich foods can reduce cancer incidence and mortality. Selenium has a role in cancer prevention, participation form many enzymes, especially glutathione peroxidase. The glutathione has antioxidant effect. It can protect cells and tissues. People can buy glutathione to maintain their normal functions. The selenium contents in sesame seeds, organ meats, garlic, mushrooms, dried shrimps, scallop, squid and amaranth are more abundant.

In addition, garlic and green tea have a different degree of inhibition on nitrite. And the green tea has most significant inhibitory effect. Garlic may inhibit and kill nitrate-reducing bacteria. It plays role in the prevention of cancers to a certain extent.Source: