Upgrading the preparation of high-quality chitosan from Procambarus clarkii wastes over the traditional isolation of shrimp chitosan

Crustacean waste is one of the most severe issues, posing significant environmental and health risks. This study aims to improve managing marine waste by isolating chitosan from Procambarus clarkii by devising a new methodology, incorporating technical steps, e.g., washing, decolorization and deacetylation under a reflexive condenser and dialysis purification. A comparison was made between the prepared P. clarkii chitosan and four types of shrimp chitosans: commercial, high, low, and nano. The obtained chitosan has a low molecular weight and viscosity compared to the commercial shrimp chitosan used in various applications. P. clarkii chitosan was prepared in high quality from a cheap source, as its color and quality were better than those of the commercial shrimp chitosan. The new methodology has successfully extracted chitosan from P. clarkii in a good quality and high purity, achieving 89% deacetylation, high solubility, high purity, and medium molecular weight. Analysis of the different chitosan samples with Fourier transform infrared spectroscopy (FTIR), atomic force microscopy, Raman spectrum referred indicated high similarity between the chitosan different types, regardless of its source. The 3D image of P. clarkii showed the distance between the highest and most profound points of extracted chitosan is 728.94 nm, revealing homogeneous, smooth surfaces, apparently free of pores and cracks. FTIR and Raman spectrum of P. clarkii indicated various functional groups, e.g., alcohol, amines, amides, and phenols. These active groups are responsible for about 60% of the antioxidant activity of that product. Evaluating the quality traits indicated the excellence of the chitosan prepared from P. clarkii, especially in color, viscosity, and antioxidant activity, nominating it for different food applications.