Butylated hydroxytoluene

Butylated hydroxytoluene or BHT (3,5-di-tert-butyl-4 hydroxytoluene) is a synthetic antioxidant which prevents oxygen-induced lipid deterioration by acting as a ‘chain breaker’ in a series of free-radical reactions.

It has a molecular structure and performance similar to BHA. Both BHA and BHT are extremely soluble in edible fats and oils and have practically no water solubility. It is susceptible to loss by volatilization and distillation under, certain food processing conditions, such as frying.

This behavior is technologically useful in food processing because the products of rancidity produce an offensive flavor, decrease the nutritional value of food, and may have deleterious health consequences when ingested.

In negative aspect of BHT, is that it may give a yellow coloration due to the formation of stilbenequinone in the presence of iron.

First patented in 1947, BHT was initially used as an industrial antioxidant in the petroleum and adhesive industries and later in the 1950s as a food and cosmetic additive. In foods, BHT may be used to a 0.02% concentration, whereas in cosmetics it is used in a 0.01% to 0.1% concentration.
Butylated hydroxytoluene