1, inulin is a linear polysaccharide formed by β- 1 2 linkage of fructose, with a glucose at the end, and the degree of polymerization DP is usually between 2 and 60. Inulin is actually a mixture of fructans with different polymerization degrees. Fructans with low degree of polymerization (DP = 2 ~ 9) are usually called fructooligosaccharides, and fructans with degree of polymerization of 10 ~ 30 are usually called fructooligosaccharides. Industrially produced inulin is mainly extracted and refined from chicory, while fructooligosaccharides are produced by acid hydrolysis of inulin or enzymolysis with inulin.

2. Both of them belong to soluble dietary fiber, which can help people get a more balanced diet, so they are often used as ingredients of high-fiber foods to improve the flavor and quality of food. Inulin and fructooligosaccharides are important prebiotics (i.e. Bifidobacterium). Inulin has a similar metabolic pathway to fructooligosaccharides in human body, and has all physiological functions of oligosaccharides. Inulin can be used by beneficial bacteria in human intestine, which can increase the value of Bifidobacterium by 5-8 times, significantly reduce harmful bacteria, improve the distribution of human flora and promote intestinal health. Inulin can promote the absorption of minerals such as calcium, magnesium and iron. Studies have shown that inulin intake can increase the absorption of important minerals (such as calcium, magnesium and iron) and increase the density of minerals in bones.