E250 – Sodium nitrite
Sodium nitrite (food additive E250) is used in the food industry as a color fixer and preservative clamp in meat and fish products. Chemical formula of sodium nitrite is: NaNO2. In pure form the additive E250 represents white hygroscopic crystal powder with slightly yellowish shade. Sodium nitrite is well dissolved in water. On air the additive E250 is exposed to slow oxidation with formation of sodium nitrate (NaNO3).
Industrial use of sodium nitrite began in 1906 when its positive properties were discovered at production of meat products and it was approved for the first time as a food additive. Now for receiving sodium nitrite in industrial production the reaction of interaction of compounds of sodium with the connections containing nitrite ion in the water environment is applied. The deposit is received during reaction, is evaporated and cooled. The received white powder also is E250 additive preservative.
Sodium nitrite is very toxic substance. The lethal dose for the person makes from 2 to 6 grams depending on the organism structure. The wrong use of a food additive E250 while production of meat or fish food can cause serious poisonings therefore the sodium nitrite is used in mixture with food salt.
Besides, a number of researches claims that though sodium nitrite itself isn't carcinogen — in certain conditions under heat treatment or in a human body it can react with the amines containing in very small quantities in food and a human body. In the result of such reaction in organism N-nitrosamines — strong carcinogens — substances can be formed which raise the risk of cancer diseases.
But it doesn't mean that it is necessary to exclude completely the products containing nitrites and nitrates from a ration (we will remind that these substances are contained in small quantities in tomatoes, potatoes and in many other vegetables and fruits), but also it isn't recommended to be fond of consumption of the food containing a large amount of nitrates and nitrites too. Also doctors advise to increase consumption of the natural products containing substances, which slow down the process of accumulation of nitrites (for example, vitamins C and E).
Nitrites are well soaked up by organism from a digestive tract. They cause the decrease in muscles tone, expansion of vessels and pressure decline. However all negative properties of nitrites can't be shown at concentration in any way, applied in the food industry. In the report of Council of the scientific questions published in the edition "American medical association" also it is said that sodium nitrite when using in food products as E250 preservative in recommended doses doesn't harm health. Scientists came to this conclusion, having had analyzed all available researches and publications on the item of use of additive E250, and also more than century experience of use of sodium nitrite in the food industry.
Sodium nitrite is an important food additive for meat production.
Addition of an additive E250 into products promotes giving them more rich red coloring, and the most important is that it protects products from oxidation and damage by bacteria. In particular sodium nitrite in the form of a food additive E250 constrains the development in products of dangerous bacteria of Clostridium botulinum which are the activators of botulism — the serious food intoxication leading to defeat of nerve system. Antimicrobic effect of E250 preservative is shown at concentrations of 50-160 mg per 1 kg of a ready-made product.
Because of high toxicity of nitrites it is desirable to refuse from their use in the food industry or at least to reduce their concentration in food, but unfortunately effective replacement of the additive E250 isn't found yet. In certain cases the additive E250 can be replaced with safe potassium sorbate (a food additive E202), but it can't give meat that coloring and aroma which nitrites give.
In the legislation of many countries the limit use rate of the additive E250 is established at the level of 50 mg per kilogram of ready-made product. In the European Union it is authorized to apply sodium nitrite only as an additive to salt in number of 0,6%. On productions where E250 preservative is used, according to the legislation strict rules of storage and work with this food additive are established.
Except use as a food additive E250, nitrite of sodium received its application in the most various industries:
- In medicine, as vasodilating, antidote at poisoning with cyanides, medicine for treatment of diseases of bronchial tubes;
- In construction as an additive to concrete for giving frost resistance;
- In the chemical industry for production of dyes and nitro connections;
- In the textile industry in processes of fabrics coloring;
- In classical photo business as reagent for photos processing.
The additive E250 is included in the list of the additives permitted for use in the food industry both in Ukraine, and in the Russian Federation.