Antioxidants
Cookbook Antioxidants are compounds that prevent or slow a chemical change called oxidation. A commonly recognized oxidation reaction is the rusting of iron, in which iron reacts with oxygen to form iron (ferrous) oxide. Heat is often released in the process of oxidation, and this is the main chemical change that occurs when a substance burns. In foods, oxidation generally contributes to spoilage, and therefore the canning process preserves food by reducing available oxygen (as well as by killing microorganisms that contribute to spoilage). In the body, many substances no longer perform their normal function when they become oxidized.
Some antioxidants are food preservatives. Sulfur dioxide is often added to dried apricots. BHT is often added to breakfast cereal packaging.
Other antioxidants guard against the effects of free radicals in the body. They are found in tea, fruits, and fungi among other things. Vitamin C, vitamin E, and lycopene are noted antioxidants.