Green and Facile Production of Chitin from Crustacean Shells Using a Natural Deep Eutectic Solvent

Natural deep eutectic solvents (NADESs) are sustainable, nontoxic, and biodegradable solvents, which are composed of natural primary metabolites. A green and efficient approach based on choline chloride-malic acid, a NADES, was developed for extracting chitin from crustacean shells, and its effectiveness for demineralization and deproteinization was determined. Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to investigate changes in the chemical composition of extracted chitin. The results revealed that most of the minerals and proteins were removed from the shrimp shells by using a NADES with the assistance of microwave irradiation. The quality of the obtained chitin was superior, and it displayed a relative crystallinity of 71%. All of these results were achieved without using harsh chemicals, which can raise environmental issues. This study provides a green and facile approach for chitin production from crustacean shells and reveals the potential of NADESs for applications in the extraction of biopolymers from natural sources.