Optimization of Deacetylation Parameters during the Extraction of Chitosan from Shrimp Shells Waste

The objective of this work was to valorize shrimp shell waste to produce chitosan by using an experimental design for the extraction. The centered composite plan was used to optimize the extraction of chitosan. The influent factors were the caustic soda concentration, the temperature and the time. Results showed that the values of answers would adapt to a second-degree polynomial model. For statistical analysis, the R-square value obtained was greater than 98.80%; the Absolute Average (AAD) was equal to zero and the Biais factor was equal to the unit, validating the model. Optimal values of caustic concentration were 67.06% while those of the temperature and the time were 100˚C and 35 min respectively. Among these factors, the concentration of caustic soda showed the greatest influence on the degree of deacetylation which varies between 74.39% and 96.02%. The optimal yield of chitosan extraction was 72.16%. Fourier Transformed Infrared (FTIR) spectrum showed absorption bands at 1650 cm−1 and 1315 cm−1 characteristic of chitosan and confirmed by morphology studies. Concentration has the greatest influence on deacetylation than temperature and time; otherwise, the viscosity increases with the pH. Shrimp shell waste converted into chitosan reduces pollution and improves their value.Subject AreasChemistry & Materials Science, Environmental Chemistry