Inulin - not to be confused with the protein hormone insulin
- is a rather variable polysaccharide built up mainly from the monosaccharide fructose, so it is sometimes known as a fructan. It is more soluble than glucose polymers: starch, glycogen etc.
Inulin is a storage carbohydrate produced by many plants
which may be considered as a component of dietary fibre. It is not digested in the first sections of the human digestive system, but in the intestine it may be digested by certain types of 'beneficial' bacteria - bifidobacteria
- which increase in number. It apparently increases calcium and possibly magnesium absorption. It is thus considered as a helpful component of functional foods - a prebiotic.
It may be formulated for use as a food additive.
On account of its fairly inert nature and solubility, inulin is sometimes used medically as a marker to measure kidney function by determining the glomerular filtration rate (GFR).
The molecule displayed here consists of
six beta (β)-fructose residues
β(2,1) glycosidic bonds,
terminated by another
to a single
. In that it has less than 10 fructose residues it may rather be described as an oligofructose.