Preparation, Optimization and Characterization of Chitosan from Different Shells of Bushehr Sea Shrimp and Its Comparison with Commercial Samples

Every year, about half or more (۴۰-۷۰%) of marine crustaceans, especially south sea aquatic animals, are disposed of as waste. It should be noted that aquatic waste, especially shrimp skin, as valuable wastes can be used to synthesize substances such as chitin and chitosan. Among the mentioned lesions, ۲۰ to ۳۰% of the external skeleton of these aquatic animals, especially crustaceans, is chitin. It is worth mentioning that, this substance is present in the structure of many edible fungi as well as plants such as yeasts and insect cuticles. By removing the acetyl groups in the chitin molecule, its most important derivative, chitosan, can be synthesized. This process was first developed by Rouget in ۱۸۵۹ through the base deacetylation of the chitin in the presence of potassium hydroxide, leading to the conversion of acetyl amine groups in chitin to amine agents and the eventual discovery of chitosan. Today, according to the contract, the number of acetyl groups in the chain determines the difference between these two polymers, and according to this contract, the presence of ۵۰% of amide groups is considered as the boundary between chitin and chitosan, ie polymers with less than ۵۰% are called chitin and more than ۵۰% is called chitosan.Important parameters such as degree of acetylation, molecular weight and crystallinity can affect the physical and chemical properties of chitin and chitosan. [۱-۴]Currently, the most important source for economically viable extraction of chitosan is the crustaceans of marine such as shrimp, crabs and krill. Chitosan can be used in the release of drugs, hemodialysis, artificial skin, meat and dairy additives, the chelating agent of heavy metal ions in wastewater treatment, and the separation of nucleic acid in thin layer chromatography. Also, due to a large number of functional groups in chitosan, it is possible to mix this polymer with a wide range of polymers. [۵-۷]The purpose of this report is to prepare, optimize and characterize chitosan from different shells of Bushehr marine shrimp and compare it with commercial samples through HNMR, XRD, FE-SEM, and FT-IR spectroscopy.