Starch is a high molecular polymer of glucose, which is hydrolyzed into maltose in disaccharide stage and glucose is obtained after complete hydrolysis. There are two types of starch: amylose and amylopectin. Amylose contains hundreds of glucose units while amylopectin contains thousands of glucose units. In natural starch, amylose accounts for about 22% ~ 26%, and the rest is amylopectin. When detected by iodine solution, amylose solution is blue, while amylopectin and iodine.

Starch is a nutrient stored in plants and exists in seeds and tubers. The starch content in all kinds of plants is high, including rice 62% ~ 86%, wheat 57% ~ 75%, corn 65% ~ 72% and potato 12% ~ 14%. This is because amylase in saliva hydrolyzes starch into disaccharide-maltose. After food enters the gastrointestinal tract, it can also be hydrolyzed by amylase secreted by the pancreas, and the formed glucose is absorbed by the small intestine wall and becomes a nutrient for human tissues. Partial hydrolysis of amylopectin can produce a mixture called dextrin. Dextrin is mainly used as food additive, glue, paste, and in the manufacture (finishing) of paper and textiles.

Starch dià

A white, odorless and tasteless granular or powdery complex carbohydrate (C 6 H 10 O 5) is the main storage form of carbohydrate in plants.