Food applications of sorbic acid and its salts.

Because of their physiological inertness, their effectiveness even in the weakly acid pH range and their neutral taste, sorbic acid and its salts have become the leading preservatives in the food sector throughout the world over the past 30 years. The most commonly used products are sorbic acid itself (E200) and potassium sorbate (E202). In many countries sodium sorbate (E201) and calcium sorbate (E203) are also permitted. Sorbic acid is sparingly soluble in water, sodium sorbate has better solubility, and potassium sorbate is very freely soluble and can be used to produce 50% stock solutions. The soluble sorbates are preferred when it is desired to use the preservative in liquid form, or when aqueous systems are to be preserved. Sodium sorbate in solid form is unstable and very rapidly undergoes oxidation on exposure to atmospheric oxygen. It is therefore not produced on the industrial scale. Aqueous solutions of sodium sorbate remain stable for some time. Calcium sorbate is used in the manufacture of fungistatic wrappers because it is highly stable to oxidation, but this use is very limited. Sorbic acid and sorbates can be directly added into the product. The products can be dipped or sprayed with aqueous solutions of sorbates. Dusting of food with dry sorbic acid is also possible but less recommended because sorbic acid irritates the skin and mucous membranes. Sorbic acid and particularly calcium sorbate can be used as active substances in fungistatic wrappers. A general survey of the numerous uses of sorbic acid in the food sector will be given. Some fields of application will be discussed that are either unimportant or not permitted in the U.K.