Natural Antioxidants In Foods

Antioxidant A compounds that can inhibit oxidative processes. Free radical A compound with an unpaired electron that can promote oxidative reaction. Free radical scavenger A compound that can absorb a free radical to decrease the radical energy thus making it less likely to cause oxidation. Metal chelators Compounds that can bind metals and decrease their […]

Natural Antioxidants In Foods

ATMOSPHERIC (TRIPLET) oxygen is a low energy biradical (i.e., contains two unpaired electrons). However, during metabolism of oxygen as well nitrogen, alterations can occur to produce highly reactive oxygen and nitrogen species that will react with and cause damage to biomolecules. In foods, this can cause oxidation of lipids, pigments, vitamins, and proteins, leading to […]

FREE RADICAL SCAVENGERS (Natural Antioxidants In Foods)

A. Phenolic Antioxidants Phenolics are compounds that have a hydroxyl group associated with an aromatic ring structure. There are numerous variations of both natural and synthetic phenolics (see Fig. 1 for examples). Natural phenolics are found predominately in the plant kingdom. Vitamin E or a-tocopherol is a plant phenolic required in the diet of humans […]

METAL CHELATORS (Natural Antioxidants In Foods)

A. Ethylene Diamine Tetraacetic Acid Transition metals will promote oxidative reactions by hydrogen abstraction and by hydroperoxide decomposition reactions that lead to the formation of free radicals. Prooxidative metal reactivity is inhibited by chela-tors. Chelators that exhibit antioxidative properties inhibit metal-catalyzed reactions by one or more of the following mechanims: prevention of metal redox cycling; […]

ANTIOXIDANT ENZYMES (Natural Antioxidants In Foods)

A. Superoxide Anion Superoxide anion is produced by the addition of an electron to molecular oxygen. Superoxide anion can promote oxidative reactions by (1) reduction of transition metals to their more prooxidative state, (2) promotion of metal release from proteins, (3) through the pH dependent formation of its conjugated acid which can directly catalyze lipid […]