Role of antioxidants in food

Abstract

Antioxidant is any substance that delays, prevents or removes oxidative damage to a target molecule. It can be found in many foods, including fruits and vegetables. The role of antioxidants in foods is to retard or control oxidation. The process of autoxidation and development of rancidity in foods involves a free radical chain mechanism via initiation, propagation and termination steps. While radicals are produced in the ‘initiation’ step, they react with unsaturated fatty acids by abstracting a hydrogen atom from a site which requires the least energy that is the allylic or diallylic position in the ‘propagation’ steps. The reactions in the propagation step make up a chain reaction until a ‘termination’ reaction occurs. Due to high stability and low volatility, it helps to maintain the level of nutrients, the texture, colour, taste, freshness, functionality, aroma, and appeal to consumers such as the older person. Various antioxidants found in food viz. natural antioxidants, synthetic antioxidants, dietary antioxidant, endogenous antioxidant play an important role in preservation of food. Vitamin C, Vitamin E, α-carotene, Lycopene, Polyphenol etc. is main sources of antioxidants. They may be present in foods as endogenous factors or may be added to preserve their lipid components from quality deterioration. The most widely used antioxidants in foods include butylated hydroxyl anisole (BHA), butylated hydroxyl toluene (BHT), propyl gallate (PG) and tertiary butyl hydroquinone (TBHQ). These antioxidants may be used at 200 ppm in bulk oils and at 200 ppm, based on the lipid content of other foods. The benefits of antioxidants include whole foods and beverages (e.g., acai berry, gogi berry, green tea) as well as isolated substances sold primarily as dietary supplements (e.g., vitamin C, lycopene, selenium) or added to foods (e.g., vitamin E). It reduces the risk of developing certain diseases such as; cancer, heart disease, stroke, and arthritis etc.