Millets: a cereal grain with potent antioxidants and health benefits

Abstract

Millet grains are small seeded Kharif crop used as food and feed. Due to presence of bioactive compounds and important minerals, millets have their own importance among cereal grains. Finger millet is a mixture of gallic acid; p-hydroxybenzoic acid; gentisic acid; caffeic acid; syringic acid; p-coumaric acid; sinapic acid; salicylic acid; trans-cinnamic acid. Foxtail millet contains gallic acid; p-hydroxybenzoic acid; vanillic; caffeic acid; chlorogenic acid; ferulic acid; sinapic acid and p-coumaric acid. Pearl millet possesses gallic acid; syringic acid; p-coumaric acid, ascorbic acid and ferulic acid. Little millet is rich in gallic acid; p-hydroxybenzoic acid; vanillic; caffeic acid; chlorogenic acid; ferulic acid; sinapic acid and p-coumaric acid. Thermal processing leads to oxidative degradation and depolymerization of bioactive constituents present in millets. Bioactive compounds like ascorbic acid and carotenoids are heat sensitive and could lose their activity upon processing especially thermal processing. Higher temperature resulted in decrease in p-coumaric acid (14.3–3.8 mg 100 g−1), ellagic acid (8.5–4.9 mg 100 g−1), caffeic acid (6.3–2.3 mg 100 g−), gallic acid (224–170 mg 100 g−1), hydroxybenzoic acid (2.3–0.6 mg 100 g−1), catechin (87.2–45.6 mg 100 g−1), ferulic acid (45.4–17.5 mg 100 g−1) and epicatechin (23.9–4.8 mg 100 g−1). Millet extracts contain specific compounds with bioactive properties, including antioxidant activity, the ability to protect DNA, anti-diabetic, anti-inflammatory and other health-promoting properties. Processing imparts specific flavor, improve texture, taste and shelf life of millets based food products. Millet grains are of great interest because of their agro-industrial importance, high nutritional value and bioactive constituents.