Development of New Method to Obtain Chitosan from the Exoskeleton of Crabs Using Microwave Radiation

In this work, chitosan was obtained from crab-uca exoskeleton (Ucides cordatus cordatus), where conversion into chitosan was made with two techniques, namely conventional heating and using microwave radiation. The product obtained by radiation (QP) and conventional process (QV) were characterized and compared to a chitosan commercial sample (QC) regarding to the deacetylation degree (GD), viscosity average molar mass (Mz) and related properties. QP presented higher GD than QV and QC samples, with values of 77%, 65% and 71%, respectively. The solubility test showed that QP dissolved more easily in diluted acetic acid than QC, while QV did not dissolve in acid aqueous solution due to the low GD. QP also showed higher Mz than QC, with values of 412.600 g/mol and 336.100 g/mol, respectively. These properties agree with those reported in the literature. Therefore, the synthesis of chitosan from chitin using microwave reaction proved to be successful, since it is easier, faster and less expensive due to the time and energy optimization in comparison to the conventional process. The chitosan sample obtained displayed even better properties than a commercial sample. In addition, this process can be adjusted for production in industrial scale.