Details:

Potassium sorbate is the potassium salt of Sorbic Acid, chemical formula C6H7KO2. It is a white salt that is very soluble in water (58.2% at 20 °C). Its primary use is as a food preservative (E number 202). 

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. While sorbic acid is naturally occurring in some berries, virtually all of the world's production of sorbic acid, from which potassium sorbate is derived, is manufactured synthetically.

Application:

Potassium sorbate is effective in a variety of applications including food, wine, and personal care products.

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. It is used in the preparation of items such as Sweet maple syrup and milkshakes served by fast food conglomerates such as McDonalds. 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. It is used in quantities at which there are no known adverse health effects, over short periods of time.Labeling of this preservative on ingredient statements reads as "potassium sorbate" 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. Tube feeding of potassium sorbate reduces gastric burden of pathogenic bacteria.

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.