Fructans are linear or branched polysaccharides composed primarily of fructose units linked by β-(2→1) or β-(2→6) glycosidic bonds, often with a terminal glucose residue. They serve as storage carbohydrates in many plants including chicory, Jerusalem artichoke, onions, and garlic. Common types include inulin (DP 2-60) and fructooligosaccharides (FOS, DP <10). Fructans function as prebiotic dietary fibers, selectively fermented by beneficial gut microbiota such as Bifidobacteria, producing short-chain fatty acids. They exhibit moderate sweetness (30-50% of sucrose), low caloric value (~1.5 kcal/g), and are used as fat replacers and texture modifiers in foods. Chemically stable under neutral pH but hydrolyze under acidic conditions or high heat. Physical properties vary with degree of polymerization; higher DP fructans show lower solubility and higher viscosity in aqueous solutions.