Potassium sorbate is the potassium salt of sorbic acid, classified as a broad-spectrum food preservative and identified by the code E202. It is one of the most widely used additives in the food industry due to its effectiveness against yeasts, moulds, and some bacteria, combined with good tolerability and a well-documented safety profile. It is chemically stable, highly water-soluble, and active across a broad pH range, with optimal efficacy in slightly acidic environments.
From a physical and sensorial standpoint, potassium sorbate appears as a white, odourless powder or crystalline granules with a neutral or slightly saline taste at higher concentrations. It does not significantly alter the aroma or texture of foods, which makes it suitable for delicate formulations.
Compositionally and functionally, potassium sorbate is characterised by:
– antimicrobial activity primarily against fungi, moulds, and yeasts;
– the ability to inhibit microbial growth by interfering with enzymatic processes in sensitive organisms;
– thermal stability, allowing use in products undergoing moderate heat treatments;
– high solubility, facilitating incorporation in liquid or semi-solid matrices;
– compatibility with other preservatives and technological ingredients.
Nutritionally, potassium sorbate does not provide calories, macronutrients, or functional dietary components. It is rapidly metabolised by the human body into water and carbon dioxide. Regulatory agencies worldwide consider it safe at permitted levels, having established an acceptable daily intake (ADI) covering all population groups.
Name breakdown and function of the components
- Potassium - Refers to the potassium element.
- Sorbate - Refers to the salt or ester of sorbic acid.
Description and function of the raw materials used in production
- Sorbic acid - A natural organic acid found in some berries, but most commercial sorbic acid is produced synthetically.
- Potassium hydroxide (or potassium carbonate) - Used to neutralize sorbic acid and form the potassium salt.
Summary of the industrial synthesis process step by step
- Neutralization - Sorbic acid is neutralized with potassium hydroxide or potassium carbonate to form potassium sorbate and water.
- Crystallization - The resulting solution is cooled to form crystals of potassium sorbate.
- Purification - The crystals are filtered, washed, and dried to obtain pure potassium sorbate.
It occurs as a white crystalline powder or white granules. It has good heat resistance and very good solubility in water.
What it is for and where
Potassium sorbate is known for its preservative properties and is commonly used as a preservative in foods, cosmetics, and personal care products to prevent the growth of molds and yeasts.
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)
Commercial applications
Food industry: Used as a preservative in many food products to prevent the growth of mold, yeast, and bacteria. It's often found in products like jams, jellies, wines, and baked goods.
Cosmetic and Skincare Products: Acts as a preservative in creams, lotions, and other skincare items.
Pharmaceutical: Might be used as a preservative in certain drug formulations.
Other Uses: Can also be used in some pet care products and certain industrial applications.
Properties
Preservative: Effective against the growth of mold and yeast.
Water-soluble: Dissolves easily in water, making it easy to incorporate into various products.
Low toxicity profile: It's generally recognized as safe (GRAS) for use in food and cosmetics at recommended concentrations.
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.
Potassium sorbate 
