Potassium sorbate

Potassium sorbate is the potassium salt of sorbic acid. Its primary use is as a food preservative (E number 202). Potassium sorbate is effective in a variety of applications including food, wine, and personal care.

Chemistry
The molecular formula of potassium sorbate is C6H7O2K and its systematic name is potassium (E,E)-hexa-2,4-dienoate. Its has a molecular weight of 150.22 g/mol. It is very soluble in water (58.2% at 20 °C). It is prepared by the reaction of sorbic acid with potassium hydroxide.

Use
Potassium sorbate is used to inhibit molds and yeasts in many foods, such as cheese, wine, yogurt, dried meats, and baked goods. 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. Labeling of this preservative reads as "potassium sorbate" on the ingredient statement. 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 affectionately 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 1,3-pentadiene. The pentadiene manifests as a typical odor of kerosene or petroleum.

Toxicology
Potassium sorbate is considered to be safe because of its long term safety record and non-toxic profile. Potassium sorbate is non-irritating and non-sensitizing. Allergic reactions are rare and it is well tolerated when administered internally.