Potassium Sorbate

CAS Number:

24634-61-5

Chemical / IUPAC Name:

(2E,4E)-potassium hexa-2,4-dienoate

INCI Name:

Potassium Sorbate

EC Number:

246-376-1

Molecular Formula:

C6H7KO2

Molecular Weight:

150.22 g/mol

Other Names:

Sorbic acid potassium salt, E202

Uses:

Potassium sorbate is the potassium salt of sorbic acid, appearing as a white to off-white crystalline powder or granules . It is a widely used, safe, and effective preservative known for its ability to inhibit the growth of molds, yeasts, and aerobic bacteria . It is considered non-toxic and participates in normal metabolism, being ultimately oxidized to water and carbon dioxide without accumulating in the body . Its toxicity is approximately half that of table salt and significantly lower than that of sodium benzoate .

· Food & Beverage Industry: Used as a preservative (E202) to extend shelf life and maintain quality in a wide variety of products, including:

  · Beverages: Soft drinks, energy drinks, and fruit juices, where it helps prevent spoilage .

  · Dairy Products: Processed cheese, yogurt, and other dairy items to inhibit mold and yeast .

  · Bakery & Confectionery: Cakes, pies, and chocolate syrups.

  · Meat & Seafood: Processed meats, bacon (in conjunction with other additives), and seafood to prevent microbial growth .

  · Desserts: Non-heat-treated plant-based mousses and fruit-flavored water-based gelatin desserts .

· Cosmetics & Personal Care: Functions as a preservative in creams, lotions, shampoos, makeup, and sunscreens. It is generally used at concentrations of 1% or lower .

· Pharmaceuticals: Used as a preservative in liquid medicines, syrups, and other pharmaceutical preparations to ensure microbiological stability.

· Wine Making: Used to inhibit the growth of molds and yeasts during fermentation and aging, helping to stabilize the wine .

Origin

Potassium sorbate is a semi-synthetic compound derived from sorbic acid. The production process involves:

· Synthesis: Sorbic acid is produced via chemical synthesis (e.g., from ketene and crotonaldehyde) or, less commonly, from natural sources like rowan berries .

· Neutralization: The resulting sorbic acid is then neutralized with potassium hydroxide to form the water-soluble potassium sorbate salt .

What does Potassium Sorbate  do in a formulation?

• Preservative / Antimicrobial Agent: Inhibits the growth of molds, yeasts, and aerobic bacteria, extending the shelf life of products. Its effectiveness is optimal at acidic pH levels (typically below pH 5-6), as it is the undissociated sorbic acid form that penetrates microbial cell membranes and disrupts metabolic functions .
• Stabilizer: Helps maintain the quality and safety of products by preventing microbial spoilage .
• Antioxidant Synergist: Can work with other preservatives (like sodium benzoate) to offer broader spectrum antimicrobial activity .

Safety Profile:

· General Hazard Classification: Recognized as Generally Recognized As Safe (GRAS) and is non-toxic when used appropriately. It is classified as having low toxicity and is considered safe for consumption within regulated limits .

· Acceptable Daily Intake (ADI): The EFSA has established a group ADI of 11 mg/kg body weight per day for sorbic acid (E 200) and its potassium salt (E 202) .

· Concentration Limits: Vary by product category. For example:

  · Non-heat-treated plant-based mousses: up to 500 mg/kg .

  · Fruit-flavored water-based gelatin desserts: up to 1000 mg/kg .

  · Beverages: typically 20-120 mg/L depending on the type .

  · Cosmetics: generally used at 1% or lower, with safety established up to 10% .

· Irritation & Sensitization: Generally regarded as non-irritating and non-sensitizing at typical use concentrations. May cause mild irritation to eyes or skin upon direct contact with concentrated powder .

· Mutagenicity Concern (Critical): Under specific conditions (in the presence of nitrites at low pH, mimicking gastric conditions), sorbate can form direct-acting mutagens such as ethylnitrolic acid and 1,4-dinitro-2-methylpyrrole. However, this formation is blocked by adequate levels of ascorbate (vitamin C), which is often co-formulated to mitigate this risk .

· Degradation & Browning: In aqueous solutions, potassium sorbate can undergo oxidative degradation during storage, which reduces its antimicrobial effectiveness and can lead to the formation of carbonyls that cause non-enzymatic browning and undesirable sensory changes .

· Handling & Storage: Store in a cool, dry place away from moisture and direct sunlight. It is hygroscopic and can be oxidized over time, leading to discoloration .

· Regulatory Status: Approved worldwide as food additive E202 . Meets FCC, USP, and various pharmacopoeia specifications. The EU has set strict purity specifications, including maximum levels for arsenic, lead, mercury, and zinc .

Technical profile: