the chemical formula of starch is: (c? H? O? ）n。

starch is a high molecular carbohydrate, which is a polysaccharide polymerized from glucose molecules. Its basic unit is α-D- glucopyranose.

There are two types of starch: amylose and amylopectin. The former has a spiral structure without branches. The latter is composed of 24~3 glucose residues connected end to end by α-1,4-glycosidic bond, and α-1,6-glycosidic bond at the branch.

Application of starch:

1. Physical modification: pregelatinized (α-gelatinized) starch, γ-ray, ultra-high frequency radiation treatment of starch, mechanical grinding treatment of starch, moist heat treatment of starch, etc.

2. Chemical denaturation: modified starch obtained by treating with various chemical reagents. There are two categories: one is to reduce the molecular weight of starch, such as acid-hydrolyzed starch, oxidized starch, baked dextrin, etc. The other is to increase the molecular weight of starch, such as cross-linked starch, esterified starch, etherified starch, grafted starch and so on.

3. Enzymatic denaturation (biological modification): starch is treated by various enzymes, such as α, β, γ-cyclodextrin, maltodextrin, amylose, etc.