Natural preservatives: Potassium Sorbate

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All packaged foods including crackers, frozen foods/dinners, protein bars, canned or pre-mixed soups contain preservatives. These additives are inevitable in food manufacturing as they help to stabilize and lengthen the shelf-life, flavor and texture of food products. A number of preservatives can be fairly simple ones like sugar or salt, or can be complex chemicals. Food preservatives are effective in keeping the eatables safe by suppressing certain reactions when food products come in contact with heat, oxygen, metals etc. Additionally, these chemicals prevent the loss of essential vitamins which play pivotal role in keeping us healthy. Most laboratory developed food preservatives are considered to be safe and well tolerated.



What is Potassium Sorbate?

Potassium sorbate is one of the safest food-grade preservatives commonly used today. The FDA has included potassium sorbate in "generally recognized as safe (GRAS)" list. This food additive is recognized with the E number 202. It is a white crystalline powder with strong antimicrobial properties. It is effective in reducing the risk of food-borne illnesses. Apart from food industry, potassium sorbate has several commercial uses in wine, and personal care product manufacturing industries. It is the inorganic salt of sorbic acid which gets readily dissolved in water and forms sorbic acid.  Interestingly, potassium sorbate does not affect the color, taste, or flavor of foods. This food additive is completely metabolized by the human body. It has the lowest allergenic potential amongst different categories of food preservatives as it is effective over a wide range of pH. This food additive prevents the growth of variety of microorganisms including yeast, molds, and fungi that attack foods. Potassium sorbate is commercially manufactured by reacting potassium hydroxide with an equimolar portion of sorbic acid. 



What are some of the physical properties of Potassium Sorbate?

  • Chemical formula: C6H7KO2 
  • IUPAC name: Potassium (2E,4E)-hexa-2,4-dienoate
  • Molar mass: 150.22 g/mol
  • Density: 1.363 g/cm3
  • Melting point: 270 °C
  • Solubility in water: 58.5 g/100 mL (100 °C)



What are uses of Potassium Sorbate?

  • Food Preservation: Potassium sorbate is a fungistat. It is used for fruits and vegetables to enhance the shelf-life and inhibit the growth of fungi and molds. Added to preserve freshness in fruit juices, tuna salads, flavored yogurt, pickles, cheeses, apple cider, cured meats, confectionaries, coleslaw, and baked goods. Typically, one tsp of potassium sorbate solution (25%) is added to 4 cups of cut fruits, before it is cooked, sterilized and canned. Potassium sorbate solution (0.2 to 0.3 %) is sprayed onto natural or processed cheeses and cream dressing in order to extend their shelf-life. Typically, fresh fish are dipped into potassium sorbate before smoking or drying. Studies have found that potassium sorbate solutions help to prevent mold growth for up to 30 days in cured meat products.
  • Wine-making: Potassium sorbate along with potassium metabisulfite is specifically used to prevent the re-fermentation of dry wines after bottling. Re-fermentation results in fizzy, yeasty wines that tastes unpleasant. This food additive does not kill the yeast already present, however, inhibits renewed growth of acetic acid and malolactic bacteria. It helps to preserve the texture and flavor of the wines.
  • Other uses: Potassium sorbate is used in a variety of personal care products such as shampoos, conditioners, body lotions, cosmetics and herbal supplements. It is conjointly utilized in pharmaceutical, tobacco and flavoring products. Also used to manufacture lubricants, plasticizers, and rubber products. Owing to its less harmful effects, many manufacturers are replacing parabens with potassium sorbate.



What are the side-effects of Potassium Sorbate?

Adults weighing less than 70 kg can safely consume 875 mg of potassium sorbate daily. Potassium Sorbate solution or sorbic acid can cause contact dermatitis at concentrations higher than 0.5%. Common allergic symptoms include severe itching of the eyes, mouth, skin, throat, nasal congestion, runny nose and abdominal pain. Some individuals suffer from migraine attack, a common adverse health effect of this preservative. Higher dosage of potassium sorbate can result in hyperkalemia. In this condition, excessive destruction of tissue increases the level of potassium in the blood. Symptoms include fatigue, nausea, and muscle weakness.


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