METHOD OF CHITOSAN PRODUCTION FROM CRUSTACEA CRUSTS Russian patent published in 2008 - IPC A23L1/33 

FIELD: technology of food products making.

SUBSTANCE: method includes grinding of chitin-containing raw material and its deproteinisation. Deproteinised raw material is mixed with concentrated 35-45%-solution of NaOH alkali with temperature of 15-25°C, the mixture being stirred at this temperature for 2-3 hours. Crushed ice is added into prepared mixture to obtain 10-15% solution of alkali, the mixture being kept until full dissolution of chitin for 8-16 hours at temperature of 0°C. Alkali NaOH is added with mixing to transparent alkaline solution of chitin obtained after separation of insoluble deposit until concentration of 50-60%. The mixture is heated to 95-120°C, chitin alkaline deacetylation being carried out for 30-120 minutes. Prepared deposit of chitosan is separated, dissolved in distilled water and neutralised to pH of at least 6.5-7.5. Deposit is separated, washed with distilled water, acetone and dried at temperature of not higher than 60°C.

EFFECT: invention allows for preparation of chitosan with even distribution of acetylated and deacetylated links in polymer molecule length.

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