Traditional processing of high-tannin sorghum grain in Uganda and its effect on tannin, protein digestibility, and rat growth

Abstract

In the southern highlands of Uganda and neighboring areas, where high-tannin sorghum [Sorghum bicolor (L.) Moench] types with soft endosperm grains are extensively grown, a unique traditional technology was evolved to process high-tannin grains before they are consumed. This technology, which is simple and uses locally available material, involves mixing high-tannin grains with wood-ash slurry, followed by soaking the grains in water overnight. The grains are then germinated for 3-4 days, dried in the sun, cleaned, and ground into flour. This wood ash treatment is shown to effectively detoxify the grain and improve the nutritional quality up to the level of low-tannin grains. The traditional technology to process high-tannin sorghum is described, and its simplicity and effectiveness in detoxification and nutritional quality improvement are demonstrated.