Inulin is a storage polysaccharide, similar to starch, present in some plants. Some plants store carbohydrates in the form of inulin as an alternative, or in addition, to starch. Inulin is present in many vegetables and fruits, including onions, leeks, garlic and bananas. Inulin is polymers consisting of approximately 35 fructose units that typically have a terminal glucose.

inulin passes directly through the small intestine without being digested or absorbed. Bacterial fermentation in the large intestine use this molecule as a food source. By products of bacterial digestion of inulin are small chain fatty acids and lactic acid. This lowers the pH of the small intestine which helps in the breakdown of insoluble calcium compounds.

Inulin has a creamy texture and its uses include the substitution for fat or sugar in foods like ice cream. This reduces the calories of foods such as ice cream, yoghurts and other dairy products, confectionary products and baked goods.