| 摘要 |
PROBLEM TO BE SOLVED: To improve the salt resistance and homogeneity of water dispersion of xanthan gum by heat treating xanthan gum while controlling the water content in a specified range to thereby control hydrogen bonding between saccharide chains and hydrogen bonding to water molecules. SOLUTION: Xanthan gum is improved by heating it at 80-150 deg.C for from 15 min to 50 hr in the presence of water vapor so that the water content becomes 1-60 wt.%. Dispersing in water at 10-100 deg.C before heating in a gas and then removing water so that the water content becomes 0-90 wt.% is effective and pref. When the heat treatment is done in the presence of oxygen, like in air, coloration is likely to occur; hence, the treatment is pref. done in an inert gas. When an aq. soln. of xanthan gum with a concn. of 0.5 wt.% is used, the viscosity (Brookfield type viscometer, 6 rpm, at 25 deg.C) of the aq. soln. after stirring at 25 deg.C for 1 hr is 2,000-25,000 mPa.s, and the viscosity of the aq. soln. of the same concn. after stirring at 80 deg.C for 1 hr is lower by 0-50% than that at 25 deg.C.
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