Sorbic acid and its potassium and calcium salts are used as preservati
ves in a large number of foods, feeds, pharmaceuticals, and cosmetics.
In the dry and crystalline state, sorbic acid is stable and no degrad
ation occurs even if stored at room temperature for a long time. Howev
er, in solutions and in foods, it undergoes autoxidation during storag
e, forming carbonyls and other compounds. Many factors (e.g., pH, temp
erature, packaging, water activity, and composition of food) influence
its stability. Degradation of sorbic acid is associated with developm
ent of browning in foods. Acetaldehyde and beta-carboxylacrolein have
been reported to be the major degradation products of sorbic acid in a
queous solutions. beta-Carboxylacrolein is found to be responsible for
sorbate-induced browning in foods as it reacts with amino acids and p
roteins to form brown pigments. Since sorbic acid mainly degrades by a
utoxidation, deoxygenation and vacuum packaging in oxygen impermeable
films or laminates have been suggested to reduce its degradation and e
nsure adequate shelf-life of sorbate-preserved foods.