Versatile acid base sustainable solvent for fast extraction of various molecular weight chitin from lobster shell.

Deep eutectic solvent (DES) prepared from choline chloride and four organic acid were evaluated for the extraction of chitin from lobster shell. It was found that the purity of chitins extracted with DESs was related to acid used. Purity of chitin extracted with choline chloride-malonic acid was the highest. Chitins extracted through DES treatment results in various molecular weight, which is associated with type of acid and temperature used during the treatment. For instance, chitin produced by malonic acid at 50 °C and 100 °C results in molecular weight of 312 KDa and 199 KDa respectively, whereas it extracted with malic acid at 100 °C results in 91 KDa. The physicochemical properties of chitins were characterized by FTIR, XRD, TG and SEM. Moreover, the CaCO3 was successfully converted into levulinic acid calcium salt which could be used as calcium supplement.

One-pot production of chitin with high purity from lobster shells using choline chloride-malonic acid deep eutectic solvent.

For the first time in this study, chitin was solely extracted from lobster shells through a fast, easy and eco-friendly method using deep eutectic solvents (DESs), consisting of mixtures of choline chloride-thiourea (CCT), choline chloride-urea (CCU), choline chloride-glycerol (CCG) and choline chloride-malonic acid (CCMA). The physiochemical properties of the isolated chitins were compared with those of the chemically prepared one and commercial one from shrimp shells. Results showed that CCT, CCU and CCG DESs had no important effect on the elimination of proteins and minerals, while chitin obtained by CCMA DES showed a high purity. The yield (20.63±3.30%) of chitin isolated by CCMA DES was higher than that (16.53±2.35%) of the chemically prepared chitin. The chitin obtained by CCMA DES could be divided into two parts with different crystallinity (67.2% and 80.6%), which also had different thermal stability. Chitin from lobster shells showed porous structure, which is expected to be used for adsorption materials and tissue engineering.