Sorbic acid

A diunsaturated carboxylic acid having the linear structural formula: CH3 - CH= CH = CH - COOH. The precursors of sorbic acid, the parasorbic acid, can be obtained naturally from the fruits of the mountain ash/Yellowberry (Sorbus aucuparia, name giver of sorbic acid).

Sorbic acid and its derivatives (potassium sorbate, calcium sorbate) serve as preservative food additives (E 200, E 202, E 203). Sorbic acid inhibits the growth of yeasts, moulds and some bacteria.

The esters/salts of sorbic acid are called sorbates.

As a preservative, sorbic acid or its salts are widely used in food (fruit, margarine, jams, bakery products, sugar solutions), pharmaceuticals, in animal feed, cleaning agents and cosmetics. In the pharmaceutical industry, sorbic acid is used as a preservative in 0.1-0.2% concentration (not in eye drops).

In wine production, the addition of a maximum of 0.2 g/l (Germany and Austria) or 1 g/l (USA) to the must or wine is permitted. Sorbic acid is used to stabilise wine against secondary fermentation by yeasts still present.

The toxicity of sorbic acid is considered to be low. In the USA, sorbic acid is labelled with the so-called GRAS status (Generally Recognized as Safe).

Type I and type IV allergies (contact urticaria, contact allergic eczema) as well as non-immunological pseudoallergies to sorbic acid have been described sporadically.

1. Alagöz S et al (2015) Effects of different sorbic acid and moisture levels on chemical and microbial qualities of sun-dried apricots during storage. Food Chem174:356-364.
2. Clemmensen O et al (1982) Perioral contact urticaria from sorbic acid and benzoic acid in a salad dressing. Contact Dermatitis 8:1-6 .
3. Dejobert Y et al (2001) Vesicular eczema and systemic contact dermatitis from sorbic acid. Contact dermatitis 45: 291.
4. Javanmardi F et al (2015) Benzoic and sorbic acid in soft drink, milk, ketchup sauce and bread by dispersive liquid-liquid microextraction coupled with HPLC. Food Addit Contam Part B Surveill 8:32-39.
5. Raison-Peyron N et al (2000) Sorbic acid: an unusual cause of systemic contact dermatitis in an infant. Contact Dermatitis 43:247-248.
6. Giordano-Labadie F et al (1996) Systemic contact dermatitis from sorbic acid. Contact dermatitis 34:61-62.
7. Scheman A et al (2012) Food avoidance diets for systemic,lip, and oral contact allergy: an american contact alternatives group article. Dermatitis 23:248-257
8. Walker R (1990)Toxicology of sorbic acid and sorbates. Food Addit Contam 7:671-676.