Introduction to Konjac – Structure

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, processing method and storage time of the raw material.

Figure 1. Konjac structure showing Glu-Glu-Man-Man units.

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.

Additional information on konjac botany, properties and health can be accessed using the arrows in the Further Reading box below.

Further Reading

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