Patent ID: 7728124

Claim:
A method for the manufacture of carboxyalkylinulin by reacting inulin with a halogenoalkylcarboxylate under alkaline conditions, characterized in that: (a) from 25 to 150 molar-%, expressed in relation to the molar amount of monosaccharide units in the inulin (100%), of the X-halogenoalkylcarboxylate, wherein the halogen is selected from chlorine, bromine and iodine, the alkyl chain contains from 1 to 5 carbon atoms, and X is an alkaline ion from the group of sodium and potassium, is dispersed into an aqueous medium, the aqueous medium containing optionally up to 35% by weight of inulin; (b) adding to and dispersing into the halogenoalkylcarboxylate medium (a) the inulin to yield a slurry, having a pH, measured on the slurry at a temperature of from 20° C. to 70° C., in the range of from about 5 to 8, containing from about 25% to about 70% by weight of the inulin, expressed in relation to the amount of water (100%-by weight) in the slurry; (c) heating the slurry (b) to a temperature from about 60° C. to about 90° C., followed by concurrently adding additional halogenoalkylcarboxylate, to yield a molar ratio of halogenoalkylcarboxylate:inulin of from 1.0 to 5.0, and an alkaline hydroxide, from the group of sodium and potassium hydroxide, in a quantity equimolar to the total level of halogenoalkylcarboxylate, plus an additional amount of the alkaline hydroxide of from 10 to 50 molar-%, expressed in relation to the molar amount of fructose units in the inulin (100%), to yield a reaction mixture pH in the range of from 8 to 12, measured at the reaction temperature (60° C. to 90° C.); (d) continuing the reaction, after all the reagents have been added, for a period up to 90 minutes, at the reaction temperature; and (e) recovering the carboxyalkylinulin reaction product in a manner known per se.