A REVIEW ON FREE RADICAL, OXIDATIVE STRESS AND ANTIOXIDANT

Oxidation is an important metabolic process in all living organisms that inevitably leads to the formation of free radicals and other reactive oxygen species (ROS). The free radicals thereby generated are extremely reactive and play a major role in multiple cellular processes such as signal transduction. Lipid peroxidation also occurs in food systems, particularly in those containing polyunsaturated fatty acids, and is a causative factor for the development of an undesirable flavour and taste, for decreased shelf life and for the formation of potentially toxic compounds in food products. Antioxidants are employed for preserving food products by retarding the deterioration resulting from oxidation, scavenging free radicals and detoxification of organisms. Currently, synthetic antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tert-butylhydroquinone and propyl gallate have been widely employed in food products for preventing the deterioration caused by oxidation and improving shelf life. Their use, however, is restricted in certain countries because of potential health issue.