Аннотация:Edible crayfish has been an object of local fishing and artificial breeding in many countries. This industry is very promising in terms of production of healthy food and by products, like biologically active polyaminosaccharide – chitosan and its derivatives. However, the crayfishing is far from the level at which it could be. This laboratory scale protocol describes a walkway from crayfish Actacus leptodactylus to chitosan and oligochitosan hydrochloride with the main emphasis on the impurities commonly present in commercial chitosan (residual heavy metals and proteins) as well as the characterization of the products by the use of inductively-coupled plasma mass spectrometry (ICP-MS), energy-dispersive X-ray spectroscopy (EDXS), protein and element analysis, 1H NMR and HP-SEC chromatography methods. The protocol includes the collection of crayfish shell waste; extraction of proteins from the waste, demineralization and separation of chitin, preparation of chitosan and oligochitosan hydrochloride. EDXS shows the presence of Al and Si residues in chitin when the deproteination of crayfish waste is carried out in an alumosilicate glass vessel while the residues are absent in the chitin deproteinated with the use of a borosilicate glass flask. ICP-MS and protein analysis show that the content of residues in chitosan and oligochitosan hydrochloride is much below the limit allowed by pharmacopoeial requirements. The study demonstrates the promise of crayfish waste as a source for the separation of chitosan and preparation of pharmaceutical grade oligochitosan.
