Sorbic acid , or 2,4-hexadienoic acid, is a natural organic compound used as a food preservative . It was first isolated from the unripe berries of the rowan ( Sorbus aucuparia ), hence its name.
1,3-Pentadiene-1-carboxylic acid /
Hexa-2,4-dienoic acid /
(E,E)-2,4-Hexadienoic acid /
Chemical formula C 6 H 8 O 2
Sorbic acid and its mineral salts, such as sodium sorbate, potassium sorbate and calcium sorbate, are antimicrobial agents often used as preservatives in food and drinks to prevent the growth of mold, yeast and fungi. In general the salts are preferred over the acid form because they are more soluble in water. The optimal pH for the antimicrobial activity is below pH 6.5 and sorbates are generally used at concentrations of 0.025% to 0.10%. Adding sorbate salts to food will however raise the pH of the food slightly so the pH may need to be adjusted to assure safety.
Sorbic acid should not be confused with other chemically unrelated, but similarly named food additives sorbitol , polysorbate , and ascorbic acid ( Vitamin C ).
Sublimation point: 60ˇăC
Boiling point (decomposes): 228ˇăC
Melting point: 134.5ˇăC
Density: 1.2 g/cm3
Solubility in water, g/100 ml at 30ˇăC: 0.25 (poor)
Vapour pressure, Pa at 20ˇăC: 1.3
Relative vapour density (air = 1): 3.87
Flash point: 127ˇăC
Octanol/water partition coefficient as log Pow: 1.33