Sprouting days: Its influence on quality characteristics of millet and sorghum flour

Sorghum and millet are among the most important cereal crops consumed worldwide, with production concentrated in many developing countries in Africa and Asia. Malting is a traditional cheap method adopted to improve sorghum and millet utilization in agribusiness and various households. This study determined the impact of sprouting duration on the quality characteristics of flours from sorghum and millet. The proximate, physicochemical and functional properties were observed in raw (0 day) and malted flours (2, 4, and 6 days). From the results, physicochemical properties generally increased (pH (4.79–6.17), TSS (1.40–5.16 ^oBrix), and TA (1.02–1.99 %)) with sprouting period for both millet and sorghum flours. Also, whilst proximate parameters such as ash (1.05–2.55 %), fat (1.69–10.55 %), and energy content (377.58–412.18 kcal) of malted millet and sorghum followed an increasing trend, fiber (1.98–1.68 %) and carbohydrate (89.10–78.67 %) decreased with increasing sprouting days. Again, with the exception of water holding capacity (1.75–2.33 %) which increased with the increase in sprouting days, all other functional properties (bulk density (0.59–0.54 g/ml), loose density (0.56–0.45 g/ml), oil holding capacity (2.50–1.45 %), and swelling index (1.07–1.02 %) declined in the malted millet flour. In the case of malted sorghum, bulk (0.64–0.59 g/ml) and loose (0.57–0.50 g/ml) densities observed a general decline while all other functional properties (water holding capacity, oil holding capacity, and swelling index of sorghum flour) revealed no obvious trend with sprouting days. This study revealed that sprouting duration has a significant impact on the quality parameters of both sorghum and millet flours. It is therefore important to explore such sprouted grain flours for possible incorporation in breakfast cereals, infant foods, and bakery products.