Preparation method of water-soluble chitosan-oligosaccharide

Abstract

A preparation method of water-soluble chitosan-oligosaccharide comprises the following steps: (1) dissolving chitosan in an acetic acid solution to prepare a chitosan acetic acid solution with a concentration of 2.0-4.0 g / ml; (2) heating to 55-65 DEG C, adding a 1-5% H2O2 solution according to a molar ratio of the chitosan to hydrogen peroxide of 1:1.5-1:2.5, adjusting the pH to be 5.5-6.5, continuously stirring for hydrolyzation to obtain a hydrolysate; (3) sampling, adding strong alkali liquor till no flocculent precipitate is generated so as to determine the hydrolysate; (4) continuously performing hydrolyzation for not more than 2 hours; (5) adding a degradation reaction terminator to obtain a preliminary product; (6) processing the preliminary product by a spray-drying process to obtain the water-soluble chitosan-oligosaccharide. Compared with the prior art, the invention has the advantages that: the degradation reaction terminator is used for controlling the degree of the degradation reaction so as to control the weight average molecular weight of the obtained chitosan-oligosaccharide; real production requirements are met; and large scale production requirements are met.

Description

technical field [0001] The invention relates to a preparation method of chitooligosaccharides. Background technique [0002] Chitin widely exists in the shells of lower plants, fungi, crustaceans and cell walls of higher plants, and is the only positively charged polysaccharide found in nature so far. Chitosan is the product of deacetylation of chitin, which is formed by condensation of 2-amino-2-deoxy-D-glucose with β-1,4 glycosidic bonds. Due to the presence of free amino groups and hydroxyl groups in chitosan molecules, it has special physiological activities, and has excellent performance in antibacterial, hypoglycemic, hypolipidemic, antitumor and immune regulation. However, its large molecular weight and poor water solubility are limited in practical applications. After chitosan is degraded into chitooligosaccharides, its water solubility is greatly improved, and it has many more superior and unique physiological activities than chitosan. Therefore, the preparation o...

AI Technical Summary

Problems solved by technology

Such as the patent No. ZL200510009669.8 Chinese invention patent "preparation method of water-soluble chitosan oligosaccharides" (authorization announcement number is CN1283668C), this patent is hydrolyzed with hydrogen peroxide after 80~100min, because the hydrolysis reaction is not terminated, directly through Freeze-drying prepared chitosan oligosaccharides, resulting in too low molecular weight of the reaction product, 609 Daltons, resulting in poor physiological activity of the product, and the introduction of Na+ in the reaction, the difficulty of separation seriously affects the quality of the product; then refer to the patent of ZL02135410.3 Chinese invention patent "A Preparation Method of Low Molecular Weight Chitosan" (authorized announcement number is CN1202136C), using H 2 o 2 with FeSO 4 The mixture degrades chitosan and introduces Fe 2+ Difficult to remove, seriously affecting the application value of the product in food and pharmaceuticals

[0007] At present, the research on the degradation of chitosan by hydrogen peroxide is mostly concentrated in the laboratory, and the research on the relevant process parameters in the degradation process, the controllability of the degradation process of hydrogen peroxide and the separation and purification of products in actual production are rarely studied. to report