Effect of sorghum variety on chemical composition and in vitro digestibility of malted grains from Botswana

Abstract

This study investigated the effects of variety of sorghum on nutritional levels of malted grains. Unscreened grains of BSH1, Mahube, Phofu and Segaolane were malted and analysed for crude protein, minerals, fiber, organic matter and in-vitro digestibility. Malts from red coloured sorghum varieties (Mahube and BSH1) had significantly higher (P<0.01) crude protein, iron, copper and zinc. This could mean malting liberated more protein, iron, copper and zinc from protein-mineral phytates and oxalates in the red coloured sorghum grains than the white coloured grains. On average, malts from white grain sorghum varieties (Segaolane and Phofu) had higher neutral detergent fiber (52.0%) than those from red coloured varieties (42.3%). While malts from red coloured grains had higher percentage of acid detergent fiber (5.6 %) than those white grains (4.5 %), they (red coloured grains) were found to be more digestible than those from white coloured grains. It may be concluded that since red coloured sorghum grains are disliked by people for their bitter taste, they may be malted and be used for animal feed and spare white coloured sorghum grains for human food. Using malted sorghum grains as substitute to maize grains in animal feeds is likely to reduce the fast rising price of chicken and pig feeds.