E202 (Potassium sorbate) is a chemical compound, an ingredient included in the list of European food additives as preservative.

Potassium sorbate is the potassium salt of sorbic acid and is produced by the reaction of sorbic acid with an equimolar portion of potassium hydroxide. It occurs as a white crystalline powder or white granules. It has good heat resistance and very good solubility in water.

What it is used for and where it is used

Food

It is a preservative, antibacterial widely used in industry as it is considered safe and reliable. It is labelled with the number E202 in the list of European additives as a preservative.

In the food sector it increases the shelf life of food and reduces the risk of bacteria (1). It has the positive characteristic of not altering the taste or colour of foods such as dried meat and dried fruit. It is mainly used in foods that are stored at room temperature or precooked, such as canned fruit and vegetables, canned fish, dried meat and desserts. It acts against moulds and is therefore often included in cheese, yoghurt, ice cream, dairy products in general, syrups and jams.

The wine industry uses it because it prevents yeast from continuing to ferment in bottles and to prevent wine from losing its flavour. 

In maize processing it is used to reduce emissions of dangerous volatile organic compounds, such as methanol, ethanol, methyl acetate, ethyl acetate and 1-propanol, preventing these gases from polluting the environment and damaging health (2).

Cosmetics

Used in detergents, shampoos, creams and body and face products to prevent the formation of mould and prolong the life of products.

It is a restricted (V/4) ingredient as a Relevant Item in the Annexes of the European Cosmetics Regulation 1223/2009.

Fragrance. It plays a decisive and important role in the formulation of cosmetic products as it provides the possibility of enhancing, masking or adding fragrance to the final product, increasing its marketability.  The consumer always expects to find a pleasant or distinctive scent in a cosmetic product.

Preservative. Any product containing organic, inorganic compounds, water, needs to be preserved from microbial contamination. Preservatives act against the development of harmful microorganisms and against oxidation of the product.

Also used in various sectors such as:

• Rubber coatings
• Automotive industry
• Detergents
• Resins (as unsaturated acid)

Compendium of the most significant studies with reference to properties, intake, effects.

Potassium sorbate studies

Typical optimal commercial product characteristics Potassium sorbate

Appearance	White to light yellow crystalline powder or white granules.
Boiling Point	233ºC at 760 mmHg
Melting Point	270°C
Density	1,361 g/cm3
Acidity	≤ 1.0 %
Flash Point	139.9ºC
Alkalinity	≤ 1.0 %
PSA	40.13000
Water Solubility	58.2 g/100 mL (20ºC)
Formaldehyde	≤ 0.1 %
Chloride as Cl, %	≤ 0.018
Pb	≤ 10 mg/kg
Arsenic	≤ 3 mg/kg
Ash	Free
Loss on Drying	≤ 1.0 %
Safety

• Molecular Formula: C₆H₇KO₂
• Molecular Weight: 150.22
• Exact Mass   150.008316
• CAS: 24634-61-5
• UNII    1VPU26JZZ4
• EC Number   246-376-1    590-00-1
• DSSTox Substance ID DTXSID7027835
• IUPAC  potassium;(2E,4E)-hexa-2,4-dienoate
• InChI=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+;  
• InChl Key      CHHHXKFHOYLYRE-STWYSWDKSA-M
• SMILES   CC=CC=CC(=O)[O-].[K+]
• MDL number  MFCD00016546
• PubChem Substance ID    329823274
• ChEBI  77868
• FEMA    2921
• Beilstein    5357554
• NACRES   NA,24
• RTECS   WG2170000
• HS   2916190090

Synonyms:

• Sorbic acid potassium salt
• Acid, Propenylacrylic
• Acid, Hexadienoic
• trans,trans-2,4-Hexadienoic acid potassium salt

References________________________________________________________________________

(1) Alagöz S, Türkyılmaz M, Tağı Ş, Özkan M. Effects of different sorbic acid and moisture levels on chemical and microbial qualities of sun-dried apricots during storage. Food Chem. 2015 May 1;174:356-64. doi: 10.1016/j.foodchem.2014.11.075.

(2) Hafner SD, Franco RB, Kung L Jr, Rotz CA, Mitloehner F. Potassium sorbate reduces production of ethanol and 2 esters in corn silage. J Dairy Sci. 2014 Dec;97(12):7870-8. doi: 10.3168/jds.2014-8537.