High-substitution carboxymethyl glutinous rice starch and preparation method thereof

Abstract

The invention relates to high-substitution carboxymethyl glutinous rice starch and a preparation method thereof. The starch is prepared by the following steps of: (1) alkali treatment of glutinous rice starch; (2) etherification reaction; (3) subsequent treatment, i.e. adding acetic acid into products obtained from step (2) for neutralization till the products are neutral, washing by using methanol water solution with the volume faction of 80% till no chloride ion exists, filtering to obtain filter cakes, and then drying and pulverizing to obtain the carboxymethyl glutinous rice starch. The carboxymethyl group substitution of the carboxymethyl glutinous rice starch is not less than 0.88; and the carboxymethyl glutinous rice starch has the advantage of high substitution, and the preparation method of the carboxymethyl glutinous rice starch has simple process, high reaction efficiency and little environment pollution.

Description

technical field [0001] The invention relates to a high degree of substitution carboxymethyl glutinous rice starch and a preparation method thereof. Background technique [0002] Carboxymethyl starch (CMS) is a cold water-soluble polymer electrolyte (also a modified starch) produced by the etherification reaction of starch with chloroacetic acid under alkaline conditions. The chemical structure, properties and functions of carboxymethyl starch are similar to those of carboxymethyl cellulose, and its development and application prospects are broad. [0003] The production of modified starch in my country is mostly based on wet process. The wet process is to disperse the starch in water or organic solvent to make a suspension with a concentration of 35-45%, add sodium hydroxide and monochloroacetic acid to the starch milk, and mix it with the chemical at a temperature lower than gelatinization. The reagents are reacted, and then filtered, washed and dried to obtain the produc...

AI Technical Summary

Problems solved by technology

The wet process has many defects: chemical reagents (catalysts, anti-gelling agents, etc.) must be added; the reaction process is long, post-processing is difficult, a large amount of water washing and long-term drying are required, and there will be a large amount of unreacted The loss of reagents and starch not only leads to low reaction efficiency, uneven substitution, and increased side reactions, but also causes a large amount of alkaline wastewater pollution, causing serious damage to the environment, and the product is severely agglomerated and difficult to crush

The main problems in the existing dry process are: when sodium hydroxide is mixed with chloroacetic acid in powder or high-concentration solution state, the chemical reaction is violent, the speed is difficult to control, the utilization rate and reaction efficiency of chloroacetic acid are low, and the produced carboxylic acid Methyl glutinous rice starch has a lower degree of substitution