Konjac mannan

Abstract

Konjac mannan is a main component of tubers of konjac which is a perennial plant of Araceae. It is a heteropolysaccharide consisting of βD- glucose (G) and βD-mannose (M), with a G/M ratio of 1 to 1.6. Konjac mannan contains very small amounts of acetyl groups and the viscosity of its aqueous solution is quite high. Deacetylation occurs with alkali treatment and a chewy irreversible gel is prepared. The gel has been used as a traditional dietary food in Japan for a long time. Konjac mannan interacts synergistically with other polysaccharides and forms thermoreversible gels. In this chapter, the following subjects are explained: cultivation of the konjac tuber, the production process and purification of konjac flour, the chemical structure and molecular weight of konjac mannan, the component analysis of commercial konjac flour, the properties of mixture gel synergistically prepared by konjac mannan and other polysaccharides, the uses and applications of konjac flour, and regulatory status.