Flowering perennial plant with tuberous roots, Amorphophallus konjac K. Koch, Araceae or closely related species such as A. bulbifer B., A. oncophyllys Prain ex Hook. f., or A. variabilis Blume. Habit. Southeast Asia. The tubers are ground to produce a flour used in traditional Asian cooking. Constit. Konjac mannan (8-10%), starch, lipid, minerals. Review of plant cultivation, production of flour and properties of konjac mannan: S. Takigami in Handbook of Hydrocolloids, G. O. Phillips, P. A. Williams, Eds. (CRC Press, Boca Raton, 2000) pp 413-424.
Nonionic, slightly branched polysaccharide. Consists of β-1,4 linked d-glucose and d-mannose in a ratio of approx 1 to 1.6, some branching at C3 of mannose, and an acetyl group attached to one per 19 sugar residues. Average mol wt 200-2000 kDa. Review of properties and applications: R. J. Tye, Food Technol. 45, 82-92 (1991); K. Nishinari in Novel Macromolecules in Food Systems, G. Doxastakis, V. Kiosseoglou, Eds. (Elsevier Science, Amsterdam, 2000) pp 309-330.