PROCESS FOR PRODUCING CHITIN AND CHITOSAN

摘要

PURPOSE: Provided is a process for producing chitin and chitosan, which improves purity and prevents molecular weight from reducing and minimizes the use of organic acids and alkali solution. CONSTITUTION: The chitin is produced by a process comprising the steps of: grinding shells of crabs; stirring and heating the ground shells in diluted NaOH solution at 80-100deg.C for 1-3 hours under nitrogen to remove protein; stirring and heating secondly for 1-3 hours in the NaOH solution to remove residual protein; neutralizing the intermediate in 0.5-1N HCl solution; reacting it by using 0.5-1N HCl solution at an ordinary temperature for 0.5-1 hours to remove calcium; adding 1-2N HCl solution and reacting for 1 hours to remove residual calcium and minerals; adjust pH to be neutral and washing; and drying it by using the natural light. And the chitosan is produced by a process comprising the steps of: preparing the chitin; soaking the chitin in KOH solution and injecting nitrogen and heating and stirring at 90-100deg.C for 3-12 hours; filtering the intermediate; reacting secondly the filtered intermediate in KOH with the same concentration under nitrogen at the same temperature; filtering and washing the chitosan; drying the chitosan under the natural light.