Optimization of chitin demineralization from shrimp shells waste by Response Surface Methodology (RSM)

The solubilization of chitosan is a very important parameter for its use in various fields. The ash content of chitosan is an important parameter because it can affect its solubility and viscosity, as well as other important characteristics. The objective of the present study is to optimize the demineralization step in the production of chitosan, using a fractional factorial experimental design, where the concentration of Hcl, the reaction time, the temperature, the size particles and the solid-liquid ratio varied. The results showed that a quadratic model was suggested for the demineralization yield and the ash rate showing high accuracy with R2 = 0.99 and 0.97, respectively. The developed models indicated a significant effect of the five studied factors except the temperature (B), and the solid-liquid ratio (E) have insignificant effects on the reaction yield. Optimal selectivity was 39.77% and 0.14% for yield and ash content respectively, reached for HCl concentration of 2N, reaction time of 0.5 h, reaction temperature of 50° C, a solid/liquid ratio (1/10 g/l) and a particle size of 1 mm. In conclusion, the conditions optimized for the demineralization process could be used for the industrial scale production of chitin for agricultural, biomedical and biotechnological purposes.