Nutritional and physico-chemical properties of flour from native and roasted whole grain pearl millet (Pennisetum glaucum [L.]R. Br.)

Abstract

The effect of roasting on the nutritional and physico-chemical properties of pearl millet flour was investigated. Pearl millet grains were subjected to different temperature-time conditions (120 °C, 140 °C for 5, 10 and 15 min and 160 °C, 180 °C for 3, 5 and 10 min). The samples were milled into flour and analyzed for their nutritional composition, amino acid profile, phenolic content and functional properties using standard methods. Protein, total ash and crude fiber contents of the flours ranged from 7.40 to 8.38%, 1.68–2.21%, 0.50–1.06%, respectively. Lysine and methionine ranged from 0.10 to 0.26 g/100 g protein, 0.01–0.06 g/100 g protein, respectively. Potassium was the dominant mineral in all samples and samples roasted at 180 °C for 10 min had the highest iron content. Roasting increased the water solubility index and oil absorption capacity of the flour samples. An increase in roasting temperature led to a significant decrease in the phenolic content of the samples. Roasting reduced some of the nutrients of the pearl millet flours and increased their functional properties.