From Wikipedia, the free encyclopedia, Potassium sorbate is the potassium salt of sorbic acid, chemical formula C6H7KO2. Its primary use is as a food preservative (E number 202).[3] Potassium sorbate is effective in a variety of applications including food, wine, and personal care products. Commercial sources are now produced by the condensation of crotonaldehyde and ketene (Ashford, 1994).
| Potassium sorbate[1][2] | |
|---|---|
 |
|
| Identifiers | |
| CAS number | 24634-61-5  |
| PubChem | 23676745 |
| ChemSpider | 4445644 |
| KEGG | D02411 |
| Jmol-3D images | Image 1 |
| Properties | |
| Molecular formula | C6H7KO2 |
| Molar mass | 150.22 g/mol |
| Appearance | white crystals |
| Odor | yes |
| Density | 1.363 g/cm3 |
| Melting point |
270 °C (decomp.)
|
| Solubility in water | 58.5 g/100 mL (100 °C) |
| Solubility |
slightly soluble in acetone
insoluble in benzene
|
| Hazards | |
| NFPA 704 | 
1
2
0
|
| LD50 | 4920 mg/kg (rat, oral) |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
|
| Infobox references | |
Properties
Potassium sorbate is produced by neutralizing potassium hydroxide with sorbic acid, an unsaturated carboxylic acid that occurs naturally in some berries. The colourless salt is very soluble in water (58.2% at 20 °C).Production
Potassium sorbate is produced by reacting sorbic acid with an equimolar portion of potassium hydroxide. The resulting potassium sorbate may be crystallized from aqueous ethanol.Most of the sorbic acid is generally prepared by a process comprising the steps of reacting crotonaldehyde with ketene in the presence of a catalyst (e.g., a fatty acid salt of zinc) to yield a polyester, and hydrolyzing the polyester with an acid or an alkali, or decomposing the polyester in a hot water. Most of the Potassium Sorbate created today is synthetic and not natural.[4] Commercial sources are now produced by the condensation of crotonaldehyde and ketene (Ashford, 1994).[5]
Uses
Potassium sorbate is used to inhibit molds and yeasts in many foods, such as cheese, wine, yogurt, dried meats, apple cider, soft drinks and fruit drinks, and baked goods.[6] It can also be found in the ingredients list of many dried fruit products. In addition, herbal dietary supplement products generally contain potassium sorbate, which acts to prevent mold and microbes and to increase shelf life, and is used in quantities at which there are no known adverse health effects, over short periods of time.[7] Labeling of this preservative on ingredient statements reads as "potassium sorbate" and or "E202". Also, it is used in many personal care products to inhibit the development of microorganisms for shelf stability. Some manufacturers are using this preservative as a replacement for parabens.Also known as "wine stabilizer", potassium sorbate produces sorbic acid when added to wine. It serves two purposes. When active fermentation has ceased and the wine is racked for the final time after clearing, potassium sorbate will render any surviving yeast incapable of multiplying. Yeast living at that moment can continue fermenting any residual sugar into CO2 and alcohol, but when they die no new yeast will be present to cause future fermentation. When a wine is sweetened before bottling, potassium sorbate is used to prevent refermentation when used in conjunction with potassium metabisulfite. It is primarily used with sweet wines, sparkling wines, and some hard ciders but may be added to table wines which exhibit difficulty in maintaining clarity after fining.
Some molds (notably some Trichoderma and Penicillium strains) and yeasts are able to detoxify sorbates by decarboxylation, producing piperylene (1,3-pentadiene). The pentadiene manifests as a typical odor of kerosene or petroleum.[8]
Toxicology
Potassium sorbate is a skin, eye and respiratory irritant,[9] although some research implies it has a long term safety record and non-toxic profile.[10]Potassium sorbate exhibits low toxicity with LD50 (rat, oral) of 4.92 g/kg,[11] similar to that of table salt.[12] Typical usage rates of potassium sorbate are 0.025% to 0.1% (see sorbic acid), which in a 100 g serving yields intake of 25 mg to 100 mg. Acceptable daily intakes for human is 12.5 mg/kg, or 875 mg daily for an average adult (70 kg), according to FAO/World Health Organization Expert Committee on Food Additives.[7]
References
- ^ Merck Index, 11th Edition, 7661.
- ^ Potassium sorbate at Sigma-Aldrich
- ^ Nordic Food Additive Database Nordic Working Group on Food Toxicology and Risk Assessment
- ^ http://www.patentstorm.us/patents/6512142/description.html patent process for commercial potassium sorbate
- ^ http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELPRDC5067082 CFNP TAP Review
- ^ Erich Lück, Martin Jager and Nico Raczek "Sorbic Acid" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2000.doi:10.1002/14356007.a24_507
- ^ a b http://www.inchem.org/documents/jecfa/jecmono/40abcj15.htm
- ^ The Soft Drinks Companion - A technical handbook for the beverage industry, Chapter 10
- ^ http://msds.chem.ox.ac.uk/PO/potassium_sorbate.html
- ^ Tulamait, Aiman; Laghi, F; Mikrut, K; Carey, RB; Budinger, GR (2005). "Potassium sorbate reduces gastric colonization in patients receiving mechanical ventilization". J Crit Care 20 (3): 281–287. doi:10.1016/j.jcrc.2005.03.002. PMID 16253799.
- ^ MSDS for potassium sorbate
- ^ MSDS for sodium chloride