Figure 2: The main source of chitin derives from the shells of crabs and shrimp. Chitin is extracted by acid treatments to dissolve calcium carbonate followed by the extraction of alkaline to solubilize the proteins. The exoskeletons of arthropods must be (i) decalcified in HCl, (ii) deprotonated in NaOH, and (iii) decolorized in KMnO4 and H2C2O4 to yield chitin. Processed chitin needs to be deacetylated in hot concentrated NaOH to produce chitosan [25,26].