Preparation of dextrin by acid hydrolysis of starch
350 ml of cold water mixed with about 10 teaspoons of starch (starch kitchen Solamyl). Slowly heat the resulting suspension in a water bath to form a clear solution of the jellied starch paste is needed to add a little water. The sebum add 30 ml of 10% sulfuric acid, the mixture boil and continuously adding water. The mixture to neutralize CaCO3 neutral to litmus paper. The mixture was filtered and the filtrate thicken crystallization.
When cooking the starch taken at regular intervals, samples of the mixture and the reaction with iodine solution (tincture of iodine-sufficient drop), we find the reaction. To terminate the reaction, the solution turns brown. Purple color in the solution contained starch. Nothing neobarví in solution is glucose.