Sodium benzoate is a chemical compound with the formula C6H5COON. In its structure, it contains a benzene ring. The formula of sodium benzoate shows that it is the sodium salt of benzoic acid. Sodium benzoate has the form of white crystalline or granular powder.
How sodium benzoate is produced
For the industrial production of sodium benzoate, toluene is used, which is oxidized in the reaction, or benzoic acid neutralized with sodium carbonate or sodium hydroxide. Sodium benzoate can be bought in industrial chemistry stores.
Sodium benzoate has bacteriostatic and fungistatic properties inhibits the development of butyric and acetic acid bacteria, yeast and mould. This action makes it used as a preservative, mainly in food. Sodium benzoate is also found in cosmetics and syrups for children and adults.
Its activity increases in the presence of sulfur dioxide, carbon dioxide, table salt, sucrose and sorbic acid. Sodium benzoate is easily absorbed from the gastrointestinal tract, in the liver, it is metabolized and finally excreted with urine in up to 24 hours.
Use of sodium benzoate – preservative E211
Sodium benzoate is mainly used as a food preservative. In the composition of food products, we find it under the designation E211. Its preservative action consists in destroying cell membranes of microorganisms and inhibiting enzymatic reactions. Preservative E211 has the strongest effect in acidic pH (in the range of 2.5-4.5). Therefore, it is most often used in products with an acidic taste, such as drinks or fruit preparations.
Sodium benzoate in beverages
In addition to the food industry, we can find sodium benzoate in cosmetics, medicines and anti-corrosive agents for storing surgical instruments, in systems that come into contact with water and in antifreeze cooling liquids. In plastics, it improves their strength, and in pyrotechnics, it is used to produce a wheezing mixture. It is also approved for the production of natural cosmetics.
E211 – is sodium benzoate harmful?
Sodium benzoate is a controversial food additive. It is considered safe if consumed less than 5 mg per kg of body weight per day. Sodium benzoate in the human body is easily metabolized and quickly excreted with urine.
Sodium benzoate in the human body
Consumption analyses show that even people who eat mainly processed food as a source of E211 do not exceed the permissible dosage of sodium benzoate in their diet. In Western societies, the main source of sodium benzoate is sweetened carbonated drinks, and in Asian countries – soy sauce. Most of E211 is eaten by Americans – 2.3 mg/kg body weight per day.
Toxic effects of sodium benzoate have been shown in studies on rats and mice, but only with huge doses of 2000-6000 mg/kg body weight, which exceeds the acceptable daily intake for humans at least 400 times. Side effects such as liver, kidney and nervous system damage were found in these experiments. No carcinogenic effect was shown. Therefore, the harmfulness of E211 occurs, but only in doses that are impossible to consume with food.
Toxic effects of sodium benzoate
However, the harmfulness of sodium benzoate can be seen by sensitive people – it can harm asthmatics, as well as people with digestive tract problems – gastritis, irritable bowel syndrome or ulcers should be the main concerns. A side effect of its excessive consumption may be an intensification of asthma and allergy symptoms. A high intake of sodium benzoate is associated with the occurrence of ADHD in adolescents.
Very often E211 occurs in fizzy drinks next to vitamin C, but sodium benzoate and vitamin C are not a good combination. They can react together, ultimately producing carcinogenic benzene.