A laboratory scale method for isolation of starch from pigmented sorghum Original Research Article

Sodium bisulfite and sodium hypochlorite at various concentrations in alkaline medium were assayed to bleach dark sorghum grains, before starch isolation. After testing different concentrations of the reagents, and time of exposure into the reagent method 2C was chosen. It used an alkaline mix of sodium hypochlorite 5.25% solution and 50 g KOH. As a result, an easy and quick method to isolate white starch from dark sorghum is reported. Percent of purity of the isolated starch from dark seed samples were compared to that exhibited by starch isolated from white sorghum grains, and slight differences between the isolates were recorded. These differences were attributed to the unequal isolation methods and/or varietal differences. The yield of the starch from dark seed samples was 30 ± 1%.