Processing of minor cereals
Maize, jowar, bajra, ragi and other small millets are important minor cereals of our country. They are also termed as coarse grains. They are widely consumed without much refinement by the poorer sections of the population, particularly in the rural areas. Judicious refining of these grains can upgrade their appearance and eating quality by removal of the unpalatable rough bran layers without affecting their nutritive quality.
Traditional milling of these grains is done by pounding in a mortar and pestle to remove the outer bran. Dry and slightly wet (soaked in water to soften the bran) and tempered grains are used. After pounding, the bran is removed by winnowing and the endosperm is ground in the same unit or small mechanical hammer/plate mills. Pounding is a very laborious and time-consuming operation and also the quality of the product is often not very good because of high moisture content of the flour and mixing of ground bran. In the mid sixties, it has been observed that when 3-5% water was mixed with the grains and tempered for 5-15 minutes, the outer bran layers were sufficiently toughened and could be abraded off (without powdering) in simple abrasive rice polishers (pearlers) without affecting the inner grain portion, which remained hard. This pearling technique has been applied successfully to jowar, bajra, varagu and wheat. The pearled grains find wide use for traditional preparations like roti, bhakri, bhath etc.