Chitin was prepared by treating and decolourizingthe shrimp crust with dilute acid and dilute alkali. The resultant product was deacetylated by alkaline treatment, and so obtained chitosan.

• 将虾壳用稀酸、稀碱处理,脱色制成甲壳质,再用碱处理脱乙酰基制成壳聚糖。