**4.6 Antioxidants**

Food polyphenols (**Table 11**) are ubiquitous components and have an antioxidant mechanism involved in fighting free radical damage by interaction of ascorbic acid and glutathione (GSH) with oxidants and oxidising agents. Scavenging of free radicals and single oxygen through food polyphenols (Vitamin E, ascorbic acid, ß-carotene and superoxide dismutase) by reduction of hydroperoxides, glutathione peroxidases (GSHPx) and catalase enzymes as well. Food polyphenols also act as chelating agent by binding with transition metals that cause cellular damage [13]. Thermal processing deteriorates the quality of maize grains due to leaching of water-soluble polyphenols into brine or sugar solution. The effects of processing method cause alteration in the structure, chemical composition and nutritional value of the food products like canned sweet corn, tortillas, chips, etc. [14].

Recently, the industry has focused attention to plant matrices rich in phytosterols and phytostanols for their ability to reduce serum cholesterol levels. Therefore, the objective of this study was to examine the phytosterol and phytostanol contents of different fractions (endosperm, pericarp, germ) of corn kernel. The phytosterols are found in the endosperm, pericarp and germ portion of corn kernel. The germ portion contains 25–31% of oil as compared to other fractions. Corn oil is enriched with ß-sitosterol (62–69%), followed by campesterol (11–18%) and stigmasterol (5–13%). Processing of maize, especially during roasting, results in the loss of phytate content and increase of the availability of minerals. For example, baking chapattis from maize helps in the reduction of phytates and improves the nutritional quality of maize. Due to the emerging field of nutraceuticals, the phytochemicals derived from maize have achieved great attention. The antioxidant capacity in terms of DPPH radical scavenging activity of maize (139 mg/100 g) is quite high as compared to other cereal and pulse grains except finger millet (173 mg/100 g). This antioxidant activity of maize helps in protecting different types of degenerative diseases [15].
