Sorbic acid was first isolated in 1859 from the unripe berries of the rowan tree (genus Sorbus) by German chemist A. W. von Hofmann. Its use as a food preservative began nearly a century later, in the 1940s, after its antimicrobial properties were discovered. Sorbic acid is a naturally occurring compound and is now the most widely used food preservative worldwide, playing a crucial role in maintaining the global food supply.
BRAND NAMES
Nutrinova: This brand is offered by Celanese and includes a full line of sorbates, such as Nutrinova Sorbic Acid, Nutrinova Potassium Sorbate, and other specialized variants.
Panosorb: Another brand from Celanese, this is a specially designed sorbic acid for protecting yeast-leavened baked goods.
MECHANISM OF ACTION
Sorbic acid works primarily by inhibiting the growth and reproduction of molds, yeasts, and certain bacteria. It disrupts microbial cells by interfering with their cellular processes, particularly by affecting the integrity of the cell membrane and inhibiting key enzymes involved in metabolism. This interference prevents the microorganisms from producing energy and essential molecules needed for growth.
PHARMACOKINETICS
Absorption:
Sorbic acid is rapidly and completely absorbed through the gastrointestinal tract and is metabolized in the body similarly to other fatty acids. Its high bioavailability and low toxicity profile are key reasons for its widespread use as a food preservative.
Distribution
Its distribution depends on the composition of the food, as it separates between the water and fat phases. Factors such as pH can also impact its solubility and effectiveness.
Metabolism
Sorbic acid is metabolized in the body through beta-oxidation, much like other fatty acids, resulting in its breakdown into carbon dioxide and water. This metabolic process accounts for its low toxicity and efficient energy production. Its biological half-life is relatively short, typically between 40 and 110 minutes.
Excretion
In the human body, sorbic acid is mainly excreted as carbon dioxide via the lungs. A small portion is converted into trans,trans-muconic acid (ttMA), which is then eliminated unchanged in the urine.
PHARMACODYNAMICS
Sorbic acid is a weak acid preservative with broad-spectrum antimicrobial properties, effective against molds, yeasts, and some bacteria. Its activity is strongest at pH levels of 6.5 or lower, where the uncharged (unionized) form can easily cross microbial cell membranes. Its main pharmacodynamic action involves interfering with cellular functions and energy production in microorganisms.
ADMINISTRATION
Sorbic acid and its salts, such as potassium sorbate, are widely used as preservatives in foods and beverages to inhibit the growth of molds, yeasts, and fungi. These compounds are usually applied by spraying, dipping, or mixing them directly into the product. While sorbic acid is the active ingredient, its salts are more commonly used due to their improved solubility in water. The established acceptable daily intake (ADI) for sorbic acid is 25 mg per kilogram of body weight.
DOSAGE AND STRENGTHS
Sorbic acid is primarily used as a food and cosmetic preservative, not a medical drug, so it does not have a standard medical dosage. The strength and application method vary widely based on the specific product and regional regulations. In food and beverages, sorbic acid and its more water-soluble salts, such as potassium sorbate, are typically used at concentrations of 0.025% to 0.3%
DRUG INTERACTIONS
Sorbic acid has few well-documented direct drug-drug interactions. One notable case is its contraindication in Difluprednate + Sorbic Acid eye drops for individuals with certain eye infections, as well as the potential for interactions with other ophthalmic medications like beta-blockers and corticosteroids. When used with topical corticosteroids, sorbic acid may reduce its own vasoconstrictive effects. Additionally, it shows more significant interactions with nonionic macromolecules, such as Tween 80, which can reduce its preservative efficacy.
FOOD INTERACTIONS
Sorbic acid is a widely used food preservative that interacts with different food components through its conjugated double bond system, resulting in both effective preservation and possible changes in product quality. These interactions are affected by factors such as pH, temperature, and the presence of other substances.
SIDE EFFECTS
Side effects from sorbic acid are rare, but it can occasionally cause allergic reactions such as skin irritation, itching, or eczema flare-ups.
OVER DOSE
An overdose of sorbic acid is rare due to its low toxicity and the body’s ability to metabolize it efficiently. However, consuming excessive amounts may potentially lead to:
Gastrointestinal discomfort (e.g., nausea, vomiting, or diarrhea)
Allergic reactions in sensitive individuals (e.g., rash, itching, or skin irritation)
Exacerbation of eczema or other inflammatory skin conditions
In large doses, sorbic acid is metabolized via beta-oxidation into carbon dioxide and water, similar to fatty acids, making it unlikely to accumulate in the body.
TOXICITY
Sorbic acid has very low toxicity and is widely considered safe for use as a food preservative at approved levels. It is metabolized by the body in the same way as other fatty acids, producing carbon dioxide and water.
