Potassium sorbate is the

potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

sorbic acid Sorbic acid, or 2,4-hexadienoic acid, is a natural organic compound used as a food preservative. It has the chemical formula and the structure . It is a colourless solid that is slightly soluble in water and sublimes readily. It was first iso ...

, structural formula CH₃CH=CH−CH=CH−CO₂K. It is a white salt that is very soluble in water (58.2% at 20 °C). It is primarily used as a food preservative (

E number E numbers, short for Europe numbers, are codes for substances used as food additives, including those found naturally in many foods, such as vitamin C, for use within the European Union (EU) and European Free Trade Association (EFTA). Commonly ...

202). Potassium sorbate is effective in a variety of applications including food, wine, and

personal care Personal care products are consumer products which are applied on various external parts of the body such as skin, hair, nails, lips, external genital and anal areas, as well as teeth and mucous membrane of the oral cavity, in order to make ...

products. While sorbic acid occurs naturally in

rowan The rowans ( or ) or mountain-ashes are shrubs or trees in the genus ''Sorbus'' of the rose family, Rosaceae. They are native throughout the cool temperate regions of the Northern Hemisphere, with the highest species diversity in the Himalaya ...

and

hippophae ''Hippophae'', from Ancient Greek ἵππος (''híppos''), meaning "horse", and φάος (''pháos''), meaning "light", is a genus of flowering plants in the family Elaeagnaceae. They are deciduous shrubs. They are exceptionally hardy plants, ...

berries, virtually all of the world's supply of sorbic acid, from which potassium sorbate is derived, is manufactured synthetically.

Production

Potassium sorbate is produced industrially by neutralizing

with

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utili ...

. The precursor sorbic acid is produced in a two-step process via the condensation of crotonaldehyde and

ketene In organic chemistry, a ketene is an organic compound of the form , where R and R' are two arbitrary valence (chemistry), monovalent functional group, chemical groups (or two separate Substituent, substitution sites in the same molecule). The na ...

Uses

Potassium sorbate is used to inhibit

mold A mold () or mould () is one of the structures that certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal ...

s and

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

s in many foods, such as cheese, wine, yogurt, dried meats,

apple cider Apple cider (also called sweet cider, soft cider, or simply cider) is the name used in the United States and Canada for an unfiltered, unsweetened, non-alcoholic beverage made from apples. Though typically referred to simply as "cider" in North ...

, dried fruits, soft drinks and fruit drinks, and baked goods.Erich Lück, Martin Jager and Nico Raczek "Sorbic Acid" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim, 2000. 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 no adverse health effects are known, over short periods of time. Labeling of this preservative on ingredient statements reads as "potassium sorbate" or "E202". Also, it is used in many

products to inhibit the development of

microorganism A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen ...

s to increase shelf stability. Some manufacturers use this preservative as a replacement for

paraben Parabens are organic compounds that are commonly used as preservatives in cosmetic and pharmaceutical products. They are esters of parahydroxybenzoic acid (also known as 4-hydroxybenzoic acid). Chemistry Structure and structure Parabens a ...

s. Also known as "wine stabilizer", potassium sorbate produces

when added to wine. It serves two purposes: * When active

fermentation Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic molecules, such as glucose or other sugars, are catabolized and reduce ...

has ceased and the wine is racked for the final time after clearing, potassium sorbate renders any surviving yeast incapable of multiplying. Yeast living at that moment can continue fermenting any residual sugar into CO₂ and

alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

, 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 wine Sparkling wine is a wine with significant levels of carbon dioxide in it, making it fizzy. While it is common to refer to this as champagne, European Union countries legally reserve that word for products exclusively produced in the Champagne ( ...

s, and some hard ciders, but may be added to

table wine Table wine (rarely abbreviated TW) is a wine term with two different meanings: a style of wine and a quality level within wine classification. In the United States, the term primarily designates a wine style: an ordinary wine which is not fort ...

s, which may not maintain their clarity after fining. * It also inhibits bacteria, especially ''

Clostridium botulinum ''Clostridium botulinum'' is a Gram-positive bacteria, gram-positive, Bacillus (shape), rod-shaped, Anaerobic organism, anaerobic, endospore, spore-forming, Motility, motile bacterium with the ability to produce botulinum toxin, which is a neurot ...

''. Tube feeding of potassium sorbate reduces the amount of pathogenic bacteria in the stomach. Some molds (notably some '' Trichoderma'' and ''

Penicillium ''Penicillium'' () is a genus of Ascomycota, ascomycetous fungus, fungi that is part of the mycobiome of many species and is of major importance in the natural environment, in food spoilage, and in food and drug production. Some members of th ...

'' strains) and

s are able to detoxify sorbates by

decarboxylation Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is ...

, producing piperylene (1,3-pentadiene). The pentadiene manifests as a typical odor of

kerosene Kerosene, or paraffin, is a combustibility, combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in Aviation fuel, aviation as well as households. Its name derives from the Greek (''kērós'') meaning " ...

petroleum Petroleum, also known as crude oil or simply oil, is a naturally occurring, yellowish-black liquid chemical mixture found in geological formations, consisting mainly of hydrocarbons. The term ''petroleum'' refers both to naturally occurring un ...

Toxicology

In pure form, potassium sorbate is a skin, eye, and respiratory irritant. Concentrations up to 0.5% are not significant skin irritants. As a food additive, potassium sorbate is used as a preservative in concentrations of 0.025%–0.1%, which in a 100 g serving yields an intake of 25–100 mg. In the United States, no more than 0.1% is allowed in fruit butters, jellies, preserves, and related products. Up to 0.4% has been studied in low-salt, naturally-fermented pickles, and when combined with calcium chloride, 0.2% made "good quality pickles." Potassium sorbate has about 74% of sorbic acid's anti-microbial activity. When calculated as sorbic acid, 0.3% is allowed in "cold pack cheese food." The upper pH limit for effectiveness is 6.5. The maximum acceptable daily intake for human consumption is 25 mg/kg, or 1.75 g daily for an average adult (70 kg). Under some conditions, particularly at high concentrations or when combined with

nitrite The nitrite polyatomic ion, ion has the chemical formula . Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name ...

s, potassium sorbate has shown genotoxic activity in vitro. Three studies conducted in the 1970s did not find it to have any carcinogenic effects in

rat Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include '' Neotoma'' (pack rats), '' Bandicota'' (bandicoo ...

References

Potassium compounds Preservatives Sorbates E-number additives

Production

Uses

Toxicology

See also

References