Effect of magnesium and iron on the hydration and hydrolysis of guar gum.
The effect that magnesium and iron have on the hydration and hydrolysis of guar gum at pH 12 was studied as a function of viscosity. It was found that small concentrations of magnesium do not affect the dissolution ratio of guar but significantly decrease hydrolysis at high temperatures. These results suggest that Mg(OH)(2) forms an adduct with the polysaccharide that prevents thermal hydrolysis of the guar. Viscosity measurements recorded in the presence of iron at pH 12 show that ferric iron inhibits hydration or dissolution of guar and may accelerate chain scission of fully hydrated guar when solutions are heated in an autoclave at 121 degrees C.
Vega-Cantu
Yadira I
YI
Department of Chemistry, Rice University, MS-60 P.O. Box 1892, Houston, Texas 77251-1892, USA.
Hauge
Robert H
RH
Norman
Lewis R
LR
Powell
Ronald J
RJ
Billups
W Edward
WE
D002236:Carbohydrate Conformation; D005685:Galactans / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007501:Iron / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D008351:Mannans / Q000737:chemistry*; D008969:Molecular Sequence Data; D053149:Plant Gums; D013696:Temperature; D013997:Time Factors; D014783:Viscosity
D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D007501:Iron; C007894:guar gum; D008274:Magnesium