benzoate of soda

benzoate of soda: see sodium benzoate.

Sodium benzoate (E211), also called benzoate of soda, has chemical formula NaC₆H₅CO₂. 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.

Uses

Sodium benzoate is a preservative. It is bacteriostatic and fungistatic under acidic conditions. It is used most prevalently in acidic foods such as salad dressings (vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (vinegar), and condiments. It is also found in alcohol-based mouthwash and silver polish. It can also be found in cough syrups like Robitussin. Sodium benzoate is declared on a product label as 'sodium benzoate' or E211. For those who can taste the chemical, it tends to be perceived as sweet, sour, 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.

Cats have a significantly lower tolerance against benzoic acid and its salts than rats and mice. Sodium benzoate is, however, allowed as an animal food additive at up to 0.1%, according to AFCO's official publication.

Mechanism of food preservation

The mechanism starts with the absorption of benzoic acid into the cell. If the intracellular pH changes to 5 or lower, the anaerobic fermentation of glucose through phosphofructokinase is decreased by 95%.

Safety and health

In combination with ascorbic acid (vitamin C, E300), sodium benzoate and potassium benzoate may form benzene, a known carcinogen. Heat, light and shelf life can affect the rate at which benzene is formed.

Professor Peter Piper of the University of Sheffield claims that sodium benzoate by itself can damage and inactivate vital parts of DNA in a cell's mitochondria. Mitochondria consume oxygen to generate ATP, the body's energy currency. If they are damaged due to disease, the cell malfunctions and may enter apoptosis. There are many illnesses now tied to DNA damage, including Parkinson's and other neurodegenerative diseases, but above all, the aging process in general.

Hyperactivity

Research published in 2007 for the UK's Food Standards Agency suggests that sodium benzoate (E211) is linked to hyperactive behaviour and decreased intelligence in children. According to the report, a high consumption of sodium benzoate is associated with a reduction in IQ of close to 5.5 points. On 6 September 2007, the British Food Standards Agency issued revised advice on certain artificial food additives, including sodium benzoate (E211).

Professor Jim Stevenson from Southampton University, and author of the report, said: "This has been a major study investigating an important area of research. The results suggest that consumption of certain mixtures of artificial food colours and sodium benzoate preservative are associated with increases in hyperactive behaviour in children.

"However, parents should not think that simply taking these additives out of food will prevent hyperactive disorders. We know that many other influences are at work but this at least is one a child can avoid."

Two mixtures of additives were tested in the research:

Mix A:

• Sunset yellow (E110)
• Tartrazine (E102)
• Carmoisine (E122)
• Ponceau 4R (E124)
• Sodium benzoate (E211)

Mix B:

• Sunset yellow (E110)
• Quinoline yellow (E104)
• Carmoisine (E122)
• Allura red (E129)
• Sodium benzoate (E211)

Sodium benzoate was included in both mixes, but the effects observed were not consistent. The Food Standards Agency therefore considers that, if real, the observed increases in hyperactive behaviour were more likely to be linked to one or more of the specific colours tested.

On 10 April 2008, the Foods Standard Agency called for a voluntary removal of the colours (but not sodium benzoate) by 2009. In addition, it recommended that there should be action to phase them out in food and drink in the European Union (EU) over a specified period.

In response to consumer insistence on a more natural product and E211's links to DNA damage and ADHD, the Coca Cola Company is in the process of phasing Sodium Benzoate out of Diet Coke. The company has stated that it plans to remove E211 from its other products - including Sprite, Fanta, and Oasis - as soon as a satisfactory alternative is discovered.

Other health effects

People who suffer from asthma, or who have recurrent urticaria, may be sensitive to sodium benzoate and have allergic reactions. Sodium benzoate and tartrazine (E102) exacerbate the condition in between 10 and 40 percent of patients with chronic urticaria, and possibly a higher proportion still of aspirin sensitive individuals.

References

External links

• Sodium Benzoate Material Safety Data Sheet
• International Programme on Chemical Safety - Benzoic Acid and Sodium Benzoate report
• pharmokinetics of the high orally administered doses used to treat hyperammonaemia
• Andersen A. Final report on the safety assessment of benzaldehyde Int J Toxicol 2006;25 Suppl 1:11-27.
• Sodium Benzoate A Cause of Hyper Kids (TIME.com)