Hydrolysis of starch by sorghum malt for maltodextrin production

Maltodextrin is a mixture of saccharides with a molecular weight between polysaccharides and oligosaccharides with DE lower than 20. Maltodextrin is more soluble in water than native starches, also is cheaper in comparison with other major edible hydrocolloids. Maltodextrin is obtained by moderate enzymatic or acidic hydrolysis of starch. The hydrolysis of starch, catalyzed by amylases, is the most important commercial enzyme process. The hydrolyzed products are widely applied in food, paper and textile industries. Because of the increasing demand for these enzymes in various industries, there is enormous interest in developing enzymes with better properties, such as raw starch-degrading amylases suitable for industrial applications and their cost-effective production techniques. Sorghum (Sorghum bicolor) is a widely grown crop in Africa. Obtaining enzymes from sorghum requires a transformation. The objective of this study was application of sorghum amylase for maltodextrin. Sorghum seeds were supplied by the ISRA (Bambey, Senegal). Seeds were germinated in the laboratory at 30°C for 72 h and the sorghum malt was dried at 40°C for 48 h. Corn starch (from Roquette, France) hydrolysis was assayed in a bioreactor of 2 l at a temperature of 65°C gently stirred. Raw starch was slurried in water (30% w/v) and sorghum malt was introduced, chloride calcium was added, pH was adjusted to 6. Maltodextrin was characterized in term of the dextrose equivalent (DE) during the hydrolysis. The yield of hydrolysis was evaluated by soluble solids (° BRIX) at different hydrolysis time. The glucose concentration released was measured by DNS method (Miller method).