What is potassium sorbate?
Potassium sorbate is a food preservative commonly used in the baking industry to prevent the growth of molds, yeasts and microorganisms. It is commonly used in cakes and icings, beverage syrups, cheese, dried fruits, margarine, pie fillings, wine, etc. Its concentration depends on the specific application. It is a water-soluble ingredient with the molecular formula C6H7KO2. Potassium sorbate is sold in the market in powder or granular form. It is effective when the pH is as high as 6, but drops rapidly at higher levels.
Potassium sorbate is produced by combining potassium hydroxide and sorbic acid to form a potassium salt. Sorbic acid is naturally present in berries in the form of lactones, such as Sorbus aucuparia L,1, which is the first to be isolated from it. Some fruits such as cranberries, blackcurrants, and strawberries naturally contain sorbic acid.
Sorbic acid is commercially produced using the ketene-crotonaldehyde condensation method. It is purified by treating sorbic acid with sodium hydroxide, hydrochloric acid and activated carbon. Potassium salt can be produced from a batch or sorbic acid production stream before drying. It is further granulated by extrusion and granulation.
Similar to other sorbates, potassium sorbate can:
- Inhibit the growth of microorganisms by changing the morphology and integrity of cell membranes.
- Destroy transportation functions and metabolic activities.
- It is more effective than other preservatives such as calcium propionate and sodium benzoate in inhibiting the growth of mold in bakery products.
- Extend product shelf life with limited impact on food quality. If used in very high concentrations, it will have an adverse effect on taste and flavor.
Potassium sorbate is usually used in chemically fermented products (dry blended with flour) in an amount of 0.03% to 0.4% of the weight of the batter. Because potassium sorbate has a damaging effect on yeast cells, it will reduce the volume of bread and produce sticky dough that is difficult to process, so it is not suitable for bread baking. Potassium sorbate can also be sprayed on the surface of products, such as corn tortillas, after baking.
In the United States, sorbic acid and potassium sorbate are considered GRAS (generally considered safe) (21 CFR 182.3089; 21 CFR 182.3225; 21 CFR 182.3640; and 21 CFR 182.3795).