Inulin is an oligomer found in plants such as chicory and Jerusalem artichoke and has a sweetening power of 30–65% that of sucrose and a high degree of polymerization (DP) of 2–60. Inulin is produced by extracting inulin from chicory roots by diffusing the roots in hot water followed by refining and last spray-drying the concentrate.
Inulin with lower a DP of 25 is generally available for high-performance fat replacement.
  Inulin is a water-soluble polymer that falls under the category of indigestible carbohydrate polymers known as fructans. It has GRAS status in the United States. 

   Inulin is a polydisperse fructan with a degree of polymerization (DP) of 2 to 60 consisting mainly of D-fructose joined by β-(2→1) linkages with a terminal D-glucose residue.A Soluble Fiber with a neutral taste, inulin resists digestion and is fermented in the colon to produce large amounts of short-chain fatty acids (SCFAs).These play a vital role in maintenance of colonic integrity and metabolism. They are produced when Dietary Fiber is fermented by colonic bacteria.SCFAs are avidly absorbed in the colon, at the same time as sodium and water absorption and bicarbonate secretion. Once absorbed, SCFAs are used preferentially as fuel for colonic epithelial cells and have trophic effects on the epithelium. SCFAs may be the effector of the beneficial role of fiber in prevention of colon cancer.