Sodium benzoate
From Wikipedia, the free encyclopedia
| Sodium benzoate | |
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| Chemical name | Sodium benzoate |
| Other names | E211, benzoate of soda |
| Chemical formula | C6H5COONa |
| Molecular mass | 144.1053 g mol−1 |
| CAS number | [532-32-1] |
| Density | 1.44 g cm−3 |
| Melting point | >300 °C |
| Boiling point | N/A |
| SMILES | O=C([O-])C1=CC=CC=C1.[Na+] |
| Disclaimer and references | |
Sodium benzoate (E211), also called benzoate of soda, has chemical formula C6H5COONa. It is the sodium salt of benzoic acid and exists in this form when dissolved in water. It can be produced by reacting sodium hydroxide with benzoic acid.
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[edit] Uses
As a food additive it is used as a preservative, effectively killing most yeasts, bacteria and fungi. Sodium benzoate is effective only in acidic conditions (pH < 3.6) making its use most prevalent in foods such as preserves, salad dressings (vinegar), carbonated drinks (carbon dioxide), jams (citric acid), fruit juices (citric acid), and chinese food sauces (soy, mustard, and duck). It is also found in alcohol-based mouthwash. More recently, sodium benzoate has become apparent in many soft drinks, including Sprite, Fanta, Sunkist and Dr Pepper. It can be identified in soft drinks by 'sodium benzoate' or E211. The taste of sodium benzoate cannot be detected by around 25 percent of the population, but for those who can taste the chemical, it tends to be perceived as sweet, salty, or sometimes bitter.
It is also used in fireworks as a fuel in whistle mix, a powder which imparts a whistling noise when compressed into a tube and ignited.
It is found naturally in cranberries, prunes, greengage plums, cinnamon, ripe cloves, and apples. Concentration as a preservative is limited by the FDA in the U.S. to 0.1% by weight though organically grown cranberries and prunes can conceivably contain levels exceeding this limit. The International Programme on Chemical Safety found no adverse effects in humans at doses of 647-825 mg/kg of body weight per day.[1][2]
Cats have a significantly lower tolerance against benzoic acid and its salts than rats and mice.[3] Sodium benzoate is however, allowed as an animal food additive at up to 0.1%, according to AFCO's official publication.[4]
[edit] Mechanism of food preservation
The mechanism starts with the absorption of benzoic acid in to the cell. If the intra cellular pH changes to 5 or lower, the anaerobic fermentation of glucose through phosphofructokinase is decreased by 95%.[5]
[edit] Safety and health
In combination with ascorbic acid (vitamin C, E300), sodium and potassium benzoate may form benzene, a known carcinogen. Heat, light and shelf life can affect the rate benzene is formed. The Food and Drug Administration (FDA) is currently (as of March 2006) performing tests, but the Environmental Working Group is calling for FDA to publicly release all tests and use their authority to force companies to reformulate to avoid the benzene forming combination.[6]
[edit] References
- ^ Concise International Chemical Assessment Document 26: BENZOIC ACID AND SODIUM BENZOATE
- ^ Cosmetic Ingredient Review Expert Panel Bindu Nair (2001). "Final Report on the Safety Assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate". Int J Tox (20 (Suppl. 3)): 23-50.
- ^ Bedford PG, Clarke EG (1972). "Experimental benzoic acid poisoning in the cat". Vet Rec (90): 53-58. PMID 4672555
- ^ AFCO (2004). "OFFICIAL PUBLICATION": 262.
- ^ Krebs HA, Wiggins D, Stubbs M (1983). "Studies on the mechanism of the antifungal action of benzoate". Biochem J (214): 657-663.
- ^ Environmental Working Group
