Lichenin

Lichenin, also known as lichenan or moss starch, is a complex glucan occurring in certain species of lichens and grains. It can be extracted from Cetraria islandica (Iceland moss). It has been studied since about 1957.

In oats and barley, lichenin can make up 6 to 8% of dry matter, whereas wheat and rye contain around 2% at the most.

It produces a gelatinous solution when boiled in water and subsequently cooled. Since humans lack the enzyme lichenase, and thus are unable to catabolize lichenin, it serves as dietary fiber. Lichenin is also used as a mucoactive agent.