Antioxidants are compounds that inhibit chemical reactions with oxygen. The term `antioxidant' refers to the activity possessed by numerous vitamins, minerals and other phytochemicals to serve as protection against the damaging effects of highly reactive molecules known as free radicals.
Free radicals are molecules that have lost an electron and try to replace it by reacting with other molecules. They can cause damage to our cells, impairing our immune system and leading to various diseases.
There are three known free radicals: the Superoxide, the Hydroxyl, and the Peroxide. They may be formed by exposure to radiation and toxic chemicals, over-exposure to the sun's rays, or through the action of various metabolic processes, such as the use of stored fat molecules for energy.
Free radical or oxidative damage can be likened to the rusting of metal. Antioxidant nutrients themselves don't become free radicals by donating an electron because they are stable in either form.
They act as scavengers, helping to prevent cell and tissue damage that could lead to cellular damage and disease.
Naturally occurring antioxidants include retinoids (vitamin A), ascorbic acid (vitamin C-found in citrus and other fruits and vegetables) and vitamin E or other related tocopherols found in many animals and plants; beta carotene, found in deep orange and dark green vegetables, are effective antioxidants.
These may play a significant role in the prevention of cancer, heart disease, immune-deficiency diseases, and ageing. Synthetic antioxidants include butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), propyl gallate and ethoxyquin.
Natural and synthetic antioxidants are added to food to prevent undesirable deterioration. Antioxidants, which are typically considered under the general category of preservative, are used to prevent the reaction of certain food constituents (primarily fat and oil or foods of animal origin, such as egg) with oxygen.
This protective effect is necessary to prevent a food or diet from spoiling, becoming rancid or discoloured. Foods preserved with antioxidants include vegetable oils, bread, and cheese. Antioxidants are also frequently applied to the packaging materials of cereals and nuts.
Source : The Hindu