Patent ID: 7648969

Claim:
A method for the preparation of low molecular weight chitosan oligosaccharides, which comprises: 1) quantitatively weighing chitosan powder, 2) adding an electrolyte solution to the chitosan powder to obtain a chitosan:electrolyte solvent (W/V) ratio=1:8˜30, wherein the electrolyte solution comprises a salt and an acid in solution, 3) stirring the solution to uniformity, then subjecting the solution to microwave irradiation, 4) adjusting the solution to neutrality with 1˜10 M NaOH, KOH or ammonia water to obtain a pale yellow floc and then settling the floc at least 30 minutes at 1˜10° C. in a cold closet, 5) filtering the pale yellow floc to obtain a precipitate and then desiccating the precipitate at 50˜70° C. to obtain a dried product, 6) crushing the dried product to 20˜100 mesh and assaying the molecular weight of chitosan oligosaccharides, and taking chitosan oligosaccharides having a molecular weight of 600˜30000 Da as the finished product.