Technology for producing high chitosan, microcrystall chitosan and water-soluble low molecular chitosan

Abstract

The production process of chitosans includes the following steps: placing the cleaned shrimp peel and crab shell as raw material into a reactor still, making deproteinization, decalcification, decolouration and deactylation to obtain flake chitosan with high deacetylation degree; then making the flake chitosan produce polymerization reaction respectively with glacial acetic acid and NaOH solutionto separate out crystal type chitosan; centrifugal-drying and pulverizing to obtain microcrystal chitosan; utilizing oxidant to cut the flake chitosan with macromolecular weight to reduce its molecular weight, then using ethyl alcohol to make precipitation, washing, vacuum-drying and pulverizing so as to obtain the water-soluble low-molecular weight chitosan product.

Description

Technical field [0001] The invention relates to a production process of sheet chitosan with high degree of deacetylation, microcrystalline high polysaccharide and water-soluble low-molecular chitosan. Background technique [0002] Chitosan (English name CHITSON) is a highly deacetylated product of chitin (CHITIN), and its chemical structure is β-(1.4)-2-amino-2-deoxy-D-glucan, which is rare in nature The positively charged polymer organics. High degree of deacetylation chitosan has the effects of inhibiting the proliferation of cancer cells, inhibiting the increase of high blood pressure, and lowering blood cholesterol. It can also be used in the treatment of burns and wounds. At present, many aspects of domestic chitosan production and application research are limited to the experimental stage. The main factors that limit the research and application of chitosan are the degree of deacetylation, water-soluble low-molecular-weight, and immature micr...

AI Technical Summary

Problems solved by technology

At present, many aspects of chitosan production and application research in China are limited to the experimental stage. The main factors that limit the research and application of chitosan are the degree of deacetylation and the immaturity of water-soluble low molecular weight and microcrystalline technology. Most manufacturers produce chitosan The technology is backward, especially the production technology of microcrystalline and water-soluble low-molecular chitosan is almost blank, and there are problems such as serious environmental pollution, low quality and low price, and low grade.

The current method of producing chitosan is generally to first soak shrimp and crab shells with 5-10% HCL solution for 16-24 hours, then deproteinize them with NaOH solution for 1 hour, and then use 0.5% KMnO 4 and 1% NaHSO 3 Decolorization, then add the decolorized raw materials into 50% NaOH solution and heat to 115-120°C in a heterogeneous state to react for 1 hour for deacetylation. The deacetylation degree reaches 85%. To achieve 95% deacetylation degree, Repeated deacetylation with NaOH solution 3-4 times, its disadvantages are occupying space, long decalcification time, decreased product viscosity, excessive KMnO 4 with NaHSO 3 The reaction produces SO 2 Harmful gas, causing serious pollution and waste of raw materials, the time to complete the entire production process is about 30 hours or more; the production of water-soluble low-molecular chitosan, currently generally adopts biological enzyme cutting technology or microbial fermentation technology, which is expensive and has impurities in the product Disadvantages of high content and difficulty in purification

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