Color fixative, also known as coloring agent, is capable of coloring substances in meat and meat products in action, so that in the food processing, preservation and other processes the meat will not be broken down or destroyed, showing a good color. This is mainly due to the nitric oxide which is produced from nitrite combine with myoglobin and hemoglobin in meat to produce nitroso nitroso-myoglobin and hemoglobin, showing out a kind of bright red. Nitrates are required to be generated by bacteria in food processing, and then get to work.
Nitrate will get reduced in the role of nitrite bacteria into nitrite in meat curing process, nitrite will be certain to transform into nitrous acid under acidic conditions. Because the mature meat after slaughtered contains lactic acid, whose pH is in the range of about 5.6 to 5.8, there is no need to add nitrous acid to make it turn into nitrous acid. Nitrous acid is very unstable, it can produce a nitroso even at room temperature. Once the nitroso is generated, it will quickly react with myoglobin from muscle tissue into bright red nitroso-myoglobin, when myoglobin nitroso is heated it will release mercapto (thiol), so that it presents nitroso original bright red color. This is the final color in the finished meat process required to be. Some products can be added starch or other ingredients in the production process to render pink, canned luncheon meat is just one example.
Nitrite has a certain toxicity, it can react with amines to generate nitrosamines a strong carcinogenic especially, so that people have been trying to select appropriate material instead. Besides its color protection, it can still corrosion, especially inhibit Clostridium botulinum to prevent botulism, also it can enhance the flavor of meat products. Until now, there is no substitutes have been found. On balance, all countries control the use strictly, in condition of ensuring the safety and quality of products. Since ascorbic acid, erythorbic acid, nicotinamide can promote protecting color (color protection additives), well ascorbic acid and α- tocopherol repress the generation of nitrosamine, so it is often combined with color fixative.
The production of canned meat in our country has been without nitrate and only nitrite. It can reduce the amount of residual products of nitrite significantly, at the same time, ensure the finished products’ color, smell, taste and texture.
The approved color according to fixative licensed in our country including sodium nitrate, sodium nitrite, potassium nitrate and potassium nitrite.