Effectively inhibiting the degradation of chitin during extraction from crustacean waste via a novel deep eutectic solvent aqueous solution

Abstract

This study proposed a feasible route for effectively inhibiting degradation of chitin by introducing a novel low-viscosity gluconic acid-based deep eutectic solvents (DESs) aqueous solution. Under the optimal extraction conditions, a high-quality chitin with molecular weight of 3.75 × 105 Da, purity of 94.5 % and yield of 79.1 % was obtained from crab shell. The maximum yield and molecular weight of chitin extracted by DESs were 1.37 times and 3.02 times higher than traditional acid/alkali method, respectively. DESs showed satisfactory recycling performance and the chitin purity could still reach 82.6 % after reusing DESs four times. Mechanism analysis confirmed that introduction of amino acids enhanced the interactions in the DESs system. The main reason for inhibiting degradation of chitin was that the reagents mainly acted on calcium carbonate and protein, without appreciable effect on the structure of chitin. This study provided a green and effective utilization strategy for crustacean waste based on multifunctional DESs systems.