Properties of Konjac Gum (Konjac Glucomannan)

Properties of Konjac Gum (Konjac Glucomannan)

 

The effective component of konjac gum is konjac glucomannan, commonly called KGM. It is one kind of soluble dietary fiber and possesses health-care functions generally recognized at home and abroad.

I. Rheological property

Konjac glucomannan is easily dispersed in water but insoluble in such organic solvents as methanol, ethanol, ethyl acetate, acetone and diethyl ether. Its hydrosol is a non-Newtonian fluid. That is to say, it possesses the shear shinning property. The apparent viscosity of its hydrosol will decrease with the increase of the shearing rate. The larger the consistency coefficient is and the smaller the flow index is, the better the quality is.

 konjac glucomannan

II. Stability

The viscosity of konjac glucomannan will decrease as the temperature increases, but it will increase again as the temperature decreases. Konjac glucomanna cannot resist high temperature over 80 ℃ for long. For example, the viscosity will decrease by 50% at the temperature of 121℃. PH value has an effect on the decrease of the viscosity, but the viscosity is relatively stable in PH 3—9. The higher the purity of konjac glucomannan is, the stronger the stability of sol is.

III. Thickening property

Konjac glucomannan is a favorable thickening agent, which is determined by its large molecular weight, strong hydratability and neutrally charged property. It is non-ionic and is affected little by salt. It can also have a synergistic thickening effect with xanthan gum and starch. For example, when 0.02—0.03% konjac gum is added to 1% xanthan gum solution, the viscosity can increase by 2 or 3 times. In addition, if we set 5% for the total amount of thickening agent, the viscosity of gelatinization by 4.5% corn modified starch and 0.5% will be 4.6—8.6 times as high as that of 5% modified starch.

 

IV. Water absorbability

The water absorbability of konjac glucomannan is determined by its purity and the higher the purity is, the stronger the water absorbability is. In general, the water absorbability reaches 80—110 times.

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On February 18th, 2013, posted in: Konjac gum, Products and Techniques by Tags:

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