Dietary antioxidants: An overview

The substances which inhibit oxidation are called as antioxidants. They are also known as free radical scavengers. The decrease in concentration of antioxidant is termed as oxidative stress. The presence of antioxidants decreases the risk of inflammation, liver disease, cardiovascular, cataract, nephrotoxicity and neurodegenerative diseases. They are categorized as exogenous and endogenous. Endogenous antioxidants include enzymatic and non-enzymatic. Enzymatic antioxidants are glutathione peroxidase, superoxide dismutase and catalase whereas non-enzymatic are uric acid, metanonin lipoic acid, glutathione and bilirubin. Exogenous are carotenoids, Vitamin E, A, C and flavonoids. Apart from natural antioxidants, synthetic antioxidants such as octyl gallate, butylated hydroxyanisole, propyl gallate, hydroxytoluene and tertbutylhydroquinone are used to enhance flavor, color extending shelf life of the product. This paper discusses on the various role of antioxidants.