Fructans are storage polysaccharides widely distributed in plants. They are present at concentrations of 15–20% in the roots of chicory (Cichorium intybus L.), 14–19% in Jerusalem artichoke (Helianthus tuberosus L.), 9–16% in garlic (Allium sativum L.), 3–7% in burdock (Arctium lappa L.), 2–6% in onion (Allium cepa L.), and 10–15% in the tuberous roots of asparagus (Asparagus officinalis). Most plant fructans are classified as either inulin type or levan type (Fig. 136.1). Inulin-type fructans are linear polymers composed of fructose units linked by β-2,1-glycosidic bonds, with a terminal sucrose unit at the reducing end. Levan-type fructans primarily consist of β-2,6-linked fructose chains, also ending with a sucrose unit. While levan-type fructans were previously described as strictly linear, the term now often encompasses molecules with β-2,1-linked branches extending from the β-2,6 backbone. Inulin-type fructans are typically found in chicory roots, Jerusalem artichoke, garlic, burdock, etc., whereas levan-type fructans are abundant in Agave species (Agave americana and Agave tequilana). Extracts from chicory roots and agave, including their partially hydrolyzed forms, are widely utilized in food applications. Naturally extracted inulin-type fructans generally have a degree of polymerization (DP) ranging from 2 to 60 (average DP ~14), while partially hydrolyzed forms have lower DPs. Additionally, enzymatically synthesized inulin-type fructans, produced by transferring fructose units from sucrose, are also available. These include fructooligosaccharides (DP 2–7) and shorter inulin (DP 2–30, average DP 14), which generally possess a lower DP than those extracted directly from plants.