Method for preparing chitin and chitosan through hydrothermal/two-step enzymic method from shrimp and crab shells and application of the method

Abstract

The invention relates to a method for preparing chitin and chitosan by coupling shrimp and crab shells through a hydrothermal/two-step enzymic method. The method comprises the following steps: removing impurities from shrimp and crab shells, and crushing the shrimp and crab shells; adding organic acid for decalcification treatment, placing filter residues into a hydrothermal reactor, and feeding a reaction medium for hydrothermal reaction; then rapidly relieving the pressure in the reactor, collecting a hydro-thermal treatment product, carrying out solid-liquid separation, and adding protease into a solid material to carry out enzymolysis deproteinization treatment; separating the deproteinized product to obtain solid residues, drying the solid residues to obtain chitin, and adding chitin deacetylase into the chitin for enzyme treatment to prepare chitosan; and finally, treating the organic acid decalcification solution and the protein enzymatic hydrolysate to obtain organic calcium and protein peptide. According to the method, the decalcified shrimp and crab shells are modified through a hydrothermal method, the compact structure of the shrimp and crab shells is broken, the accessibility of subsequent protease and deacetylase is promoted, the enzymolysis efficiency is improved, poly-generation of organic acid calcium, protein peptide, chitin and chitosan is achieved, the production process is rapid, stable and free of pollution, and large-scale industrial application is easy to achieve.

Description

technical field [0001] The invention belongs to the technical field of comprehensive utilization of aquatic product processing waste, in particular to a method and application for preparing chitin and chitosan by coupled hydrothermal-two-step enzymatic method of shrimp and crab shells. Background technique [0002] Shrimp and crab shells are solid wastes produced during the processing of aquaculture and belong to the residues of primary agricultural product processing. With the development of artificial shrimp farming and aquatic product processing in China, the amount of these solid wastes is increasing. It is estimated that 0.5-0.6 tons of leftovers such as shrimp shells are produced for every ton of shrimp produced. At present, my country's aquatic shrimp and crab products are estimated to be 15 million tons (dry weight) per year, producing more than 5 million tons of crustacean biomass waste such as shrimp and crab shells, which can form an industrial scale of more than...

AI Technical Summary

Problems solved by technology

[0012] The purpose of the present invention is to provide a shrimp and crab shell hydrothermal solution for the disadvantages of a large number of shrimp and crab shells in the coastal areas of our country that are backward in processing technology, resulting in low-value utilization of resources, and using a large amount of acid and alkali in the processing process, causing serious environmental pollution and other shortcomings. - The method and application of two-step enzymatic coupling to prepare chitin and chitosan. This method uses hydrothermal method to modify decalcified shrimp and crab shells, crack its dense structure, promote the accessibility of subsequent proteases and deacetylases, and improve High enzymatic hydrolysis efficiency, realizing concatenation of calcium organic acid, protein peptide, chitin and chitosan, fast, stable and pollution-free production process, easy to realize large-scale industrial application