METHOD FOR OBTAINING CHITOSAN Russian patent published in 2019 - IPC C08B37/08 

FIELD: food industry.

SUBSTANCE: invention relates to the food industry. Method involves following operations. Deproteinization of the chitin-containing mycelium of Aspergillus niger fungus is carried out by a single treatment with a 3–5 % solution of sodium hydroxide for 60 minutes at a temperature of 60 °C, deacetylation – 8–12 % solution of sodium hydroxide for 150–180 min at a temperature of 55–65 °C, then separating the resulting precipitate, drying it to a moisture content of 8–12 %, grinding and treating it with a 1 % solution of hydrochloric or acetic acid at room temperature for 45 minutes. Resulting mass is filtered and chitosan is isolated from the liquid phase by precipitation with 25 % ammonium hydroxide solution or 22 % sodium hydroxide solution until pH 10 is reached. Chitosan, obtained in the result, has the maximum equilibrium sorption capacity for ions by (Cu²⁺) of 380–400 mg/g sorbent, and the yield of chitosan is 21.8–24.2 % on the dry weight of the original mycelium.

EFFECT: invention makes it possible to obtain chitosan with a high sorption capacity with respect to copper ions (Cu²⁺) and with a high yield of the desired product.

1 cl, 1 dwg, 2 tbl, 3 ex