Effects of Fermentation and Roasting on Natural Antioxidants in Maize

Natural antioxidants in foods are well appreciated for preserving foods and had been shown to have beneficial effects against oxidative stress-induced degenerative and age-related diseases, cancer, and aging. This chapter reviewed the effects of two major primary processing methods; fermentation and roasting on the antioxidant properties of maize and its products. The effect of fermentation and roasting on the chemical active compounds including carotenoids, vitamin C, phenolics, and flavonoids, and the scavenging antioxidants power of both aqueous and organic extracts of fermented and roasted maize using DPPH and ABTS assays were reported. Fermentation results in the modification of cereals' phytochemicals; caroteniods content of maize increases due to fermentation with improved scavenging power of fermented maize extract. The effect of roasting includes increased antioxidant activity and content, development of brown colouration and improved flavour due to the presence of Maillard reaction products. These changes contribute to better health benefits by enhancing the digestibility of nutrients and the activity of available antioxidants. Intakes of roasted fresh or dried maize varieties; especially, QPM are highly recommended to ameliorate the causes of night blindness, lung and prostate cancers.