Food additives are substances added to food to improve appearance, taste, texture or to preserve food. There are several types of food additives including preservatives, antioxidants, flavorings, stabilizers, thickeners, and dyes. Preservatives like salt, sugar, and sodium nitrate prevent the growth of microorganisms. Antioxidants such as BHA, BHT and vitamin C prevent oxidation and rancidity. Food additives can make food last longer and improve qualities but some are associated with health issues.