What are the functions and advantages and disadvantages of food colorants

Color retention agent is an additive that is often used in meat products. In my country's latest national standard of food additives GB2760-2011, it is stipulated that potassium nitrate, sodium nitrate, potassium nitrite, etc. can be added as color retention agents in prescribed amounts.
However, the role of these color retention agents is to make meat products color. The principle is this: nitrate is reduced to nitrite under the action of nitrous bacteria, which produces free nitrous acid under acidic conditions and decomposes to produce sub After the nitro group, it combines with myoglobin in the muscle to form nitrosomyoglobin, which makes the meat products show a stable bright red.
Advantages:
1. Nitrite has an inhibitory effect on Clostridium botulinum;
2, can make meat products show a stable and attractive bright red;
3. Improve the flavor of meat products.
Disadvantages:
1. Nitrate and nitrite still have a certain toxic effect on the human body. Nitrate will be reduced to nitrite in the gastrointestinal tract. When the body ingests a large amount of it, it can cause intestinal cyanosis, so nausea and Poisoning symptoms such as vomiting, general weakness, and bruising of the skin. In severe cases, coma, convulsions, respiratory failure and death may occur. It is because hemoglobin is oxidized to methemoglobin;
2. Nitrite is also a precursor to the formation of nitrosamines. It synthesizes nitrosamines with amines in the stomach and is potentially carcinogenic. Therefore, the amount of color-preserving agents should be strictly controlled in meat products.