Structure of Konjac Glucomannan
The primary component in Konjac
flour from Amorphophallus Konjac species is konjac glucomannan (KGM), a high molecular polysaccharide. The structure of KGM as residues of mannose and glucose, linked together by β-1,4 with a molar ratio of 1.6:1.0. It is a slightly branched polysaccharide having a molecular weight of 200,000 to 2,000,000 Daltons (actual molecular weight of KGM depends on the konjac variety,
|Figure 1. Konjac structure showing Glu-Glu-Man-Man units.|
processing method and storage time of the raw material. Like all natural hydrocolloids, the molecular weight of KGM decreases by heating, duration time in processing and storage duration. Some glucose residues contain side chains composed of β-1,4 glucose residues linked at the glucose 3 positions along the backbone. One side chain occurs per 3,280 glucose residues, and on each side chain are several glucose residues. Acetyl groups along the Glucomannan backbone contribute to the solubility properties and are located, on average every 9 to 19 sugar units.