Potassium Sorbate
Promel Potasyum Sorbat is the readily water-soluble potassium salt of sorbic acid (E202), used to extend shelf life by inhibiting the growth of moulds and yeasts in dairy products and other foods.
Product description
Potassium sorbate is the potassium salt of sorbic acid (2,4-hexadienoic acid, E200), an unsaturated fatty acid, and is identified by the E number E202. Because it is far more soluble in water than sorbic acid, it offers practical advantages in aqueous systems, brines and suspensions. It is one of the most widely used antifungal preservatives in the food industry.
Technical function and mode of action
When potassium sorbate dissolves in water, an equilibrium is established between the sorbate ion and undissociated sorbic acid. The greater part of the antimicrobial effect comes from the undissociated sorbic acid, which penetrates the cell membrane and disrupts intracellular enzyme systems (particularly dehydrogenases) and membrane transport functions. The pKa of sorbic acid is 4.76; consequently, as the pH of the medium decreases, the proportion of undissociated acid—and therefore efficacy—increases. Above pH 6, efficacy drops markedly.
Sorbates are highly effective against moulds and yeasts but have only limited activity against certain bacteria. Because lactic acid bacteria are relatively resistant, the impact on cultures in fermented products is limited. Some mould species can degrade sorbate to form 1,3-pentadiene, which causes a petroleum- or plastic-like off-odour on the cheese surface. For this reason, sorbate should be used as a preventive measure under good hygiene conditions, not as a corrective treatment for high mould loads.
Applications
- Processed cheese and cheese spreads (where permitted by regulations)
- Pre-packaged, sliced or grated cheeses
- Cheese surface treatments and coatings
- Dairy desserts, filling creams and sauces
- Other food categories such as meat products, bakery products and beverages
Benefits
- Extended shelf life through broad-spectrum activity against moulds and yeasts
- High water solubility for easy preparation and dosing
- Effective protection in low- and medium-pH products
- Minimal impact on taste and odour at recommended dosages
- An economical and widely accepted preservative
Usage and dosage
Potassium sorbate can be incorporated by direct addition to the product mass, dissolved in water before addition, or applied to the cheese surface by dipping or spraying as a solution. In processed cheese, it can be added together with other dry ingredients during cooking. For calculation purposes, note that 1.34 g of potassium sorbate is equivalent to approximately 1 g of sorbic acid; maximum permitted levels in regulations are expressed as sorbic acid.
The Turkish Food Codex Food Additives Regulation and EU Regulation No 1333/2008 specify the product categories in which sorbates may be used and the maximum permitted levels on a category-by-category basis. For example, in the EU, limits of 1000 mg/kg apply to pre-packaged sliced ripened cheeses and 2000 mg/kg to processed cheese; in plain fermented milk products, the use of preservatives is generally not permitted. The current limits for your specific product category must always be verified before application. Optimum dosage should be determined through pilot trials based on product pH, water activity and target shelf life.
A technical data sheet (TDS) is available on request.
Packaging and storage
Store in a cool, dry place away from light, with the packaging tightly sealed. Moisture and light can accelerate oxidation and discolouration of sorbate.
Frequently asked questions
Should I use sorbate or natamycin?
Natamycin is effective at very low doses, remains on the surface and is designed for surface application on cheeses. Sorbate, on the other hand, can be incorporated into the product mass and used across a wide range of products including processed cheese, sauces and desserts. The choice depends on the product type and regulatory permissions.
Why does a petroleum-like off-odour develop in cheese?
Certain mould species convert sorbate into 1,3-pentadiene. This typically occurs when a high mould load is combined with an insufficient sorbate concentration; good hygiene and an adequate dose are the preventive measures.
Does sorbate affect starter cultures?
Lactic acid bacteria are relatively resistant to sorbate; however, at high doses fermentation may slow down, so pilot trials are recommended in cultured products.
Technical support
Contact the Technofood technical team for support on regulatory-compliant dosage of potassium sorbate in your product and its combination with other preservatives.