sorbic acid

Sometimes confused with ascorbic acid, Vitamin C.

Sorbic acid
IUPAC name	(2E,4E)-hexa-2,4-dienoic acid
Identifiers
CAS number	110-44-1 Y
SMILES	CC=CC=CC(O)O
Properties
Molecular formula	C6H8O2
Molar mass	112.12 g/mol
Melting point	135 °C
Boiling point	228 °C (dec)
Acidity (pKa)	4.76 at 25 °C
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Sorbic acid, or 2,4-hexadienoic acid, is a natural organic compound used as a food preservative. It has the chemical formula C₆H₈O₂. It was first isolated from the unripe berries of the Rowan (Sorbus aucuparia), hence its name.

Sorbic acid and its mineral salts, such as sodium sorbate, potassium sorbate and calcium sorbate, are antimicrobial agents often used as preservatives in food and drinks to prevent the growth of mold, yeast and fungi. In general the salts are preferred over the acid form because they are more soluble in water. The optimal pH for the antimicrobial activity is below pH 6.5 and sorbates are generally used at concentrations of 0.025% to 0.10%. Adding sorbate salts to food will however raise the pH of the food slightly so the pH may need to be adjusted to assure safety.

Sorbic acid is also used as a bio descaling agent.

Sorbic acid should not be confused with other chemically unrelated, but similarly named food additives sorbitol, polysorbate, and ascorbic acid (Vitamin C).

The E numbers are:

• E200 Sorbic acid
• E201 Sodium sorbate
• E202 Potassium sorbate
• E203 Calcium sorbate

Some molds (notably some Trichoderma and Penicillium strains) and yeasts are able to detoxify sorbates by decarboxylation, producing trans-1,3-pentadiene. The pentadiene manifests as a typical odor of kerosene or petroleum. Other detoxification reactions include reduction to 4-hexenol and 4-hexanoic acid.^[1]

See also

• Acids in wine

References

This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (September 2007)

1. ^ "Fungal metabolites of sorbic acid. Food Research Centre, Sheffield City Polytechnic, UK.". http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2253810&dopt=Abstract. 

External links

• Sorbic acid on chm.bris.ac.uk
• Sorbic inchem.org
• MSDS at University of Oxford