Towards a greener future: Exploring the challenges of extraction of chitin and chitosan as bioactive polysaccharides

Chitin is among the most abundant natural biopolymers in the world and a major constituent of various aquatic and terrestrial organisms, including crustaceans, insects, fungi, and algae. Chitin and chitosan are widely used in various applications due to their interesting biological and physicochemical characteristics such as being non-toxic, biodegradable and biocompatible. This paper provides a comprehensive overview of the varied sources of chitin and chitosan, offering a comparative analysis of commonly employed extraction methods. The discussion includes a nuanced exploration of the advantages and limitations associated with each approach. Furthermore, the paper delves into contemporary applications of chitin and chitosan across diverse fields. The emergence of green, environmentally-friendly extraction methods to mitigate environmental impact is the focus of attention. Particularly noteworthy is the utilization of deep eutectic solvents (DES), which play a pivotal role in revolutionizing alternative approaches for chitin recovery from biomass. These solvents not only enable chitin to be efficiently extracted, but also recovered for subsequent use, facilitating multiple extraction cycles. Even today, DES are being studied for their potential use in the extraction of chitosan from biomass, suggesting a promising future for their broader application in biopolymer extraction.