- Inulin is a naturally occurring polysaccharide belonging to the fructan family, characterized by chains of fructose molecules typically linked through β-(2→1) glycosidic bonds, often ending with a single glucose unit.
- It is considered a storage carbohydrate in many plants, especially in the roots and tubers of species such as chicory (Cichorium intybus), Jerusalem artichoke (Helianthus tuberosus), and dandelion. Unlike starch, which is composed of glucose polymers, inulin is built primarily from fructose units, which gives it distinct physicochemical and nutritional properties. Its degree of polymerization can range from just a few fructose units (short-chain inulin, also called oligofructose) to more than 60 units in long-chain inulin.
- In the plant kingdom, inulin serves as an important energy reserve and plays a role in stress tolerance. Plants that store inulin instead of starch often thrive in temperate regions, where inulin accumulation supports resistance to cold and drought. Inulin’s solubility and ability to retain water also contribute to osmoregulation within plant tissues, helping maintain cellular stability under environmental fluctuations.
- For humans, inulin is significant because it is classified as a dietary fiber and prebiotic. Since humans lack the enzymes to hydrolyze β-(2→1) fructosidic linkages, inulin passes undigested through the upper gastrointestinal tract and reaches the colon, where it is fermented by beneficial gut bacteria such as Bifidobacterium and Lactobacillus. This selective stimulation of gut microbiota contributes to improved digestive health, enhanced mineral absorption, and potential modulation of the immune system. Research also indicates that inulin consumption may help regulate blood glucose and lipid levels, making it valuable in dietary strategies for managing diabetes, obesity, and cardiovascular risk.
- In the food industry, inulin is prized for its multifunctionality. It acts as a fat replacer, bulking agent, and stabilizer, allowing the creation of reduced-calorie or low-fat products without sacrificing texture and mouthfeel. Its mild sweetness and ability to improve creaminess make it a popular ingredient in dairy alternatives, baked goods, confectionery, and beverages. Moreover, inulin’s low caloric value and lack of effect on blood sugar make it suitable for diabetic and weight-management diets.
- Beyond food, inulin has potential applications in medicine and biotechnology. It has been explored as a carrier for drug delivery, as a protective agent for probiotics, and as a functional additive in pharmaceutical formulations. Because inulin and its derivatives can be chemically modified, researchers are investigating its role in biomaterials and controlled-release systems. Additionally, its fermentation into short-chain fatty acids, such as butyrate, provides systemic health benefits linked to colon health and reduced risk of colorectal diseases.
