Fructans are polymers of fructose often with a terminal glucose. They are classified into five groups based on glycosidic linkage: (a) inulin with β-(2,1)-linkages, (b) levan/phlein with β-(2,6)-linkages, (c) graminin with both β-(2,1)-linkages and β-(2,6)-linkages, (d) inulin neoseries and (e) levan neoseries. They are commonly found in vacuoles of grasses and other angiosperms as storage carbohydrates.