Abstract:

Starch is the plant energy storage polysaccharide in nature, usually occurring as granules. A starch from a specific plant source is unique among starches, i.e., starch granules from the various plant sources differ in appearance, particle size distribution, fine structure of the constituent polymer molecules and physical properties. Granular starch is generally composed of two types of molecules, amylose and amylopectin. Amylose is a predominantly linear （1,4）-α-D-glucan, although some amylose molecules are slightly branched. Amylopectin has a branch-on-branch structure consisting of mostly short chains of （1,4）-linked α-D-glucopyranosyl units linked to other short, linear chains via α-（1,6） branch points. The amylopectin fraction is composed of much larger molecules than those of amylose. Different molecular structures and size, amylose/amylopectin ratios, and granular architectures give each type of starch its unique properties. Due to the special characteristics of native non-toxicity, renewability, broad sources and biodegradability, starch has been widely used in food, medicine, papermaking industry, cosmetics, etc. Furthermore, after physical, chemical and biological modification, starch can be endowed with more diverse molecular structure and more abundant functional properties, which may greatly improve its applied properties and extend its application fields. Herein, the structure, source, physical and chemical properties, typical production methods, main modification methods and recent application advance of starch are introduced, and the research trend and development prospect of starch in the future are also pointed out.

Key words: starch, modified starch, source, structure, preparation, property, application