potassium sorbate
{{short description|Chemical compound}}
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 477163963
| Reference =Merck Index, 11th Edition, 7661.[http://www.sigmaaldrich.com/US/en/product/sial/85520 |SIAL&N5=SEARCH_CONCAT_PNO|BRAND_KEY&F=SPEC Potassium sorbate] at Sigma-Aldrich.
| ImageFile =Potassium sorbate.svg
| ImageSize =
| ImageName = The structure of potassium sorbate
| ImageFile1 = Potassium sorbate ball-and-stick.png
| ImageSize1 =
| PIN = Potassium (2E,4E)-hexa-2,4-dienoate
| OtherNames = {{Unbulleted list|E202|Sorbistat-K|Sorbistat potassium}}
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 4445644
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D02411
| InChI = 1/C6H8O2.K/c1-2-3-4-5-6(7)8;/h2-5H,1H3,(H,7,8);/q;+1/p-1/b3-2+,5-4+;
| InChIKey = CHHHXKFHOYLYRE-ZCSOUONQBI
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C6H8O2.K/c1-2-3-4-5-6(7)8;/h2-5H,1H3,(H,7,8);/q;+1/p-1/b3-2+,5-4+;
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = CHHHXKFHOYLYRE-STWYSWDKSA-M
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 24634-61-5
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 1VPU26JZZ4
| PubChem = 23676745
| ChEBI_Ref = {{ebicite|changed|EBI}}
| ChEBI = 77868
| SMILES = [K+].[O-]C(=O)\C=C\C=C\C
}}
|Section2={{Chembox Properties
| C=6 | H=7 | K=1 | O=2
| Appearance = White crystals
| Odor = Yes
| Density = 1.363 g/cm3
| MeltingPtC = 270
| MeltingPt_notes = decomposes
| BoilingPt =
| Solubility = 58.5{{nbsp}}g/100{{nnbsp}}mL (100{{nbsp}}°C)
| SolubleOther = {{ubli
| Soluble in ethanol, propylene glycol
| Slightly soluble in acetone
| Very slightly soluble in chloroform, corn oil, ether
| Insoluble in benzene
}}
| Solvent = other solvents
}}
|Section3={{Chembox Hazards
| NFPA-H = 2
| NFPA-F = 1
| NFPA-R = 0
| MainHazards =
| FlashPt =
| AutoignitionPt =
| LD50 = 4920{{nbsp}}mg/kg (oral, rat){{cite book | title=Sax's Dangerous Properties of Industrial Materials | publisher=Wiley | date=2004-10-15 | isbn=978-0-471-47662-7 | doi=10.1002/0471701343 | page=3043 | editor-last1=Lewis | editor-first1=Richard J. }}
}}
}}
Potassium sorbate is the potassium salt of sorbic acid, 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 202).[http://www.norfad.dk/FoodAddDetails.asp?ENumber=E+202 Nordic Food Additive Database] {{webarchive|url=https://web.archive.org/web/20080502102138/http://www.norfad.dk/FoodAddDetails.asp?ENumber=E+202 |date=2008-05-02 }} Nordic Working Group on Food Toxicology and Risk Assessment. Potassium sorbate is effective in a variety of applications including food, wine, and personal care products. While sorbic acid occurs naturally in rowan and hippophae 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 sorbic acid with potassium hydroxide. The precursor sorbic acid is produced in a two-step process via the condensation of crotonaldehyde and ketene.Erich Lück, Martin Jager and Nico Raczek "Sorbic Acid" in Ullmann's Encyclopedia of Industrial Chemistry, 2011, Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a24_507.pub2}}[http://www.patentstorm.us/patents/6512142/description.html patent process for commercial potassium sorbate] {{webarchive|url=https://web.archive.org/web/20120131004448/http://www.patentstorm.us/patents/6512142/description.html |date=2012-01-31 }}{{cite web|url=http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELPRDC5067082|title=Agricultural Marketing Service|website=www.ams.usda.gov|access-date=2012-09-21|archive-date=2014-06-11|archive-url=https://web.archive.org/web/20140611194224/http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELPRDC5067082|url-status=dead}}
Uses
Potassium sorbate is used to inhibit molds and yeasts in many foods, such as cheese, wine, yogurt, dried meats, apple cider, 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.{{doi|10.1002/14356007.a24_507}} 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 personal care products to inhibit the development of microorganisms to increase shelf stability. Some manufacturers use 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 renders 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 may not maintain their clarity after fining.
- It also inhibits bacteria, especially Clostridium botulinum.{{cite journal | vauthors = Sofos JN, Busta FF, Bhothipaksa K, Allen CE, Robach MC, Paquette MW |title=Effects of various concentrations of sodium nitrite and potassium sorbate on Clostridium botulinum toxin production in commercially prepared bacon |journal=Journal of Food Science |date=September 1980 |volume=45 |issue=5 |pages=1285–1292 |doi=10.1111/j.1365-2621.1980.tb06539.x}} Tube feeding of potassium sorbate reduces the amount of pathogenic bacteria in the stomach.{{cite journal |doi= 10.1016/j.jcrc.2005.03.002 |title= Potassium sorbate reduces gastric colonization in patients receiving mechanical ventilization |first5= G. R. Scott |last5= Budinger |first4= Roberta B. |last4= Carey |first3= Kathleen |last3= Mikrut |journal= J. Crit. Care |first2= Franco |year= 2005 |volume= 20 |last2= Laghi |issue= 3 |pages= 281–287 |last1= Tulamait |first1= Aiman |pmid= 16253799 |display-authors= 3 }}
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.The Soft Drinks Companion – A technical handbook for the beverage industry, Chapter 10.
Toxicology
In pure form, potassium sorbate is a skin, eye, and respiratory irritant.{{cite web|url= http://www.chemone.com/default/msds/Potassium%20sorbate.pdf|title= Potassium Sorbate|publisher= Chem One, Ltd.|date= 2010-06-14|access-date= 2015-05-04}}{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}{{cite web |publisher=National Institute of Health |title=Sorbic Acid - National Library of Medicine HSDB Database |url=https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+590}} Concentrations up to 0.5% are not significant skin irritants.{{cite journal|author=Elder, R. E. |year=1988 |title=Final report on the safety assessment of sorbic acid and potassium sorbate. |journal=J Am Coll Toxicol |volume=7 |issue=6 |pages=837–880 |url=https://pdfs.semanticscholar.org/bbbe/1de833dfb7ebaf3959eaace0762e9b9ffb9b.pdf |archive-url=https://web.archive.org/web/20180527201422/https://pdfs.semanticscholar.org/bbbe/1de833dfb7ebaf3959eaace0762e9b9ffb9b.pdf |url-status=dead |archive-date=May 27, 2018 |access-date=May 26, 2018|doi=10.3109/10915818809078711 |s2cid=5998542 }}
As a food additive, potassium sorbate is used as a preservative in concentrations of 0.025%–0.1%,{{cite web |title=Potassium sorbate - Agricultural Marketing Service - USDA |url=https://www.ams.usda.gov/sites/default/files/media/P%20Sor%20technical%20advisory%20panel%20report.pdf |publisher=U.S. government |quote=Potassium sorbate is effective against yeasts, molds, and select bacteria, and is widely used at 0.025 to 0.10 % levels in cheeses, dips, yogurt, sour cream, bread, cakes, pies and fillings, baking mixes, doughs, icings, fudges, toppings, beverages, margarine, salads, fermented and acidified vegetables, olives, fruit products, dressings, smoked and salted fish, confections and mayonnaise. |access-date=May 26, 2018}} 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.{{cite web|title=21 CFR 150 - Fruit butters, jellies, preserves, and related products |publisher=Government Printing Office |date=April 1, 2011 |url=https://www.gpo.gov/fdsys/pkg/CFR-2011-title21-vol2/pdf/CFR-2011-title21-vol2-part150.pdf |access-date=May 25, 2018}} 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."{{cite journal |last1=Guillou |first1=A.A. |last2=Floros |first2=J.D. |last3=Cousin|first3=M.A. |title=Calcium Chloride and Potassium Sorbate Reduce Sodium Chloride used during Natural Cucumber Fermentation and Storage |journal=Journal of Food Science |volume=57 |issue=6|year=1992 |pages=1364–1368 |issn=0022-1147 |doi=10.1111/j.1365-2621.1992.tb06859.x}} 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."{{cite web|title=21 CFR 133 - Cheeses and related cheese products |publisher=Government Printing Office |date=April 1, 2011 |url=https://www.gpo.gov/fdsys/pkg/CFR-2011-title21-vol2/pdf/CFR-2011-title21-vol2-part133.pdf |access-date=May 25, 2018}} 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).{{cite web|url=http://www.inchem.org/documents/jecfa/jecmono/40abcj15.htm |title=036. Sorbate, potassium (FAO Nutrition Meetings Report Series 40abc) |publisher=Inchem.org |access-date=2013-02-22}}{{cite journal | last1=Carocho | first1=Márcio | last2=Barreiro | first2=Maria Filomena | last3=Morales | first3=Patricia | last4=Ferreira | first4=Isabel C. F. R. | title=Adding Molecules to Food, Pros and Cons: A Review on Synthetic and Natural Food Additives | journal=Comprehensive Reviews in Food Science and Food Safety | volume=13 | issue=4 | year=2014 | pages=377–399 | doi=10.1111/1541-4337.12065| pmid=33412697 | hdl=10198/12042 | hdl-access=free }} Under some conditions, particularly at high concentrations or when combined with nitrites, potassium sorbate has shown genotoxic activity in vitro.
Three studies conducted in the 1970s did not find it to have any carcinogenic effects in rats.{{Cite journal | doi = 10.1016/S0015-6264(76)80173-3 | title = Long-term toxicity studies of sorbic acid in mice | year = 1976 | last1 = Hendy | first1 = R. J. | last2 = Hardy | first2 = J. | last3 = Gaunt | first3 = I. F. | last4 = Kiss | first4 = I. S. | last5 = Butterworth | first5 = K. R. | journal = Food and Cosmetics Toxicology | volume = 14 | issue = 5 | pages = 381–386 | pmid = 1010505 }}{{Cite journal | doi = 10.1016/0015-6264(75)90080-2 | title = Long-term toxicity of sorbic acid in the rat | year = 1975 | last1 = Gaunt | first1 = I. F. | last2 = Butterworth | first2 = K. R. | last3 = Hardy | first3 = J. | last4 = Gangolli | first4 = S. D. | journal = Food and Cosmetics Toxicology | volume = 13 | issue = 1 | pages = 31–45 | pmid = 1123201 }}{{Cite journal | doi = 10.1016/S0015-6264(76)80174-5 | title = Long-term toxicity of parasorbic acid in rats | year = 1976 | last1 = Mason | first1 = P. L. | last2 = Gaunt | first2 = I. F. | last3 = Hardy | first3 = J. | last4 = Kiss | first4 = I. S. | last5 = Butterworth | first5 = K. R. | last6 = Gangolli | first6 = S. D. | journal = Food and Cosmetics Toxicology | volume = 14 | issue = 5 | pages = 387–394| pmid = 1010506 }}
See also
- Sodium benzoate{{Cite journal|last=Saltmarsh|first=Mike|date=2015-03-15|title=Recent trends in the use of food additives in the United Kingdom|journal=Journal of the Science of Food and Agriculture|volume=95|issue=4|pages=649–652|doi=10.1002/jsfa.6715|issn=1097-0010|pmid=24789520|bibcode=2015JSFA...95..649S |quote=... the preservative used in the study, sodium benzoate, has been replaced by potassium sorbate in the majority of soft drinks.}}