The substance that makes tough crustacean shells is not calcium but chitin. It is the second most abundant natural polysaccharide polymer on earth after cellulose in plants.
The chitin, which takes advantage of the “waste” of processing these seafood products, is used to produce chitosan, a valuable, versatile, and versatile material for the manufacture of many industrial and commercial products. , health … essential for life.
Shrimp shells, chitin and chitosan
The shrimp shell has a chitin-protein structure that hardens the surface due to the deposition of calcium salts and other organic matter.
Chitin is a straight-line polysaccharide, a polymer of many N-acetyl-glucosamine units connected by bridges.
Chitin is a straight-line polysaccharide, a polymer of many N-acetyl-glucosamine units connected by cầu-1,4glucoside bridge. Because the natural chitin in shrimp shells is often associated with proteins, lipids, calcium, pigments … it is often necessary to clean before using them to produce chitosan. The two main steps to purifying chitin are: acid demineralization and alkaline protein reduction or an protease enzyme
Chitosan is closely related to chitin, chitin is heated in a concentrated caustic soda solution of acetyl radicals and chitin is converted to chitosan. This is a straight-line polysaccharide, a polymer of D1,4 glucosamine molecules.
In nature, chitin is also present in many forms: quite pure (caterpillars), in very thin layers (butterfly wings, with excellent color effect), along with the proteins that make up sclerotin (the main substance in the set). outer bones of insects) … ..
