Millets in sub-Saharan Africa: a review of the nutritional and bioactive composition, methods of processing and its developed products

Millet grains are essential foods for most people living in rural areas with low socioeconomic status, especially in Asia and sub-Saharan Africa (SSA). The most cultivated millets in SSA are pearl millet (Pennisetum glaucum), finger millet (Eleusine coracana), fonio (Digitaria exilis), and teff (Eragrostis tef). Others from around the world are Japanese Barnyard millet (Echinochloa frumantacea); foxtail millet (Setaria italica) and proso millet (Panicum miliaceum), Kodo millet (Paspalum scrobiculatum), and little millet (Panicum sumatrense). The main databases used for this review paper were Web of Science and Scopus. Science Direct and Google Scholar were also used for identifying keywords. The total number of articles used were 110. This review paper explored the origin, physical structure, nutritional composition, and phytochemicals of millet grains. The effect of different processing methods on the nutritional, antinutritional and bioactive compounds of millet products was discussed. Moreover, some traditional products made from these grains were reviewed. The challenges that pertain to the migration from major cereals to millet-based products and future perspectives were given. We advocate the need to create value-added products from these underutilised millets species for commercialisation and food security in line with the second sustainable development goal.