Processing, composition, and technological properties of decorticated, sprouted, and extruded pearl millet (Pennisetum glaucum (L.) R. Br.) flours

Abstract

AbstractPearl millet (Pennisetum glaucum (L.) R. Br.) is a gluten‐free cereal with potential use in food security and human nutrition; however, it is still relatively unknown by the food industry and by most consumers. In order to evaluate the impact of processing on the nutritional and technological characteristics of pearl millet flours, three different processing methods (decortication, sprouting, and extrusion) were studied. The effects of processing methods on the particle size distribution, proximate composition, mineral content, bulk density, water absorption index, water solubility index (WSI), and pasting properties (rapid visco analyzer) on the flours were evaluated and compared with whole raw flour. The whole raw flour showed particles size of 355 μm, 62.5% carbohydrate, 12.0% protein, 5.6% lipid, 8.2% dietary fiber, and 1.7% ash. Decorticated flour presented decrease in mineral, dietary fiber, and protein content. The extruded flour presented the highest WSI and the lowest lipid content and paste viscosity, whereas sprouted flour showed low setback, paste viscosity, phytate content, and high protein and dietary fiber content. Decorticated and sprouted flour presented the highest luminosity, whereas extruded flours the smallest L*. The increasing color difference (ΔE*) between raw pearl millet and processed flours was sprouted < decorticated < extruded. The production of millet flour should be encouraged for various food applications, especially in Brazil, which has a large cultivated area of this cereal used only for animal feed and an expanding gluten‐free market.Practical applicationsThe impact of pre‐processing methods on millet grains drives its application in the food industry. All processed flours have the potential to be used as a gluten‐free ingredient for celiacs, people with non‐celiac gluten sensitivity, and for food‐style adepts. The extruded flour has the potential to be used in the development of soups, powder drink, snacks, and breakfast cereal, whereas the sprouted flour can be used in frozen and bakery products. The decorticated flour could be explored as a substitute in different food preparations, such as biscuits, pastas, and breads.