Recent advances in the application of deep eutectic solvents (DESs) as plasticizers in the production of chitosan-based packaging films

Background The environmental drawbacks of the synthetic plastics and additives used in packaging occasioned the transition to sustainable and eco-friendly food packaging systems, which implies the use of biopolymers from renewable sources. Chitosan is a biopolymer derived from renewable sources, which provides promising materials for food packaging due to its biodegradable, bioactive, and functional properties. Nonetheless, chitosan-based films require the incorporation of plasticizers to improve their characteristics. Recently, the plasticizing effect of deep eutectic solvents (DESs) has been proved to be prominent and efficient. The introduction of DESs as plasticizers in chitosan-based packaging materials offers sustainable and green pathways for the development of packaging systems. Scope and approach This review explores the recent advances in the development of chitosan-based films, focusing on the use of DESs as plasticizers. We elucidated the production and characteristics of chitosan-based films and the plasticizer behavior of DESs. This review provides a global view of the factors affecting plasticizer properties of DESs for the formation of chitosan-based films. The application of DESs and chitosan-based films for food packaging has been outlined along with the challenges. Key findings and conclusions The most common procedure for producing chitosan-based films is casting. DESs have emerged as a new generation of green plasticizers due to their unique physicochemical characteristics and environmental advantages. The use of DESs as plasticizers in chitosan-based films improves the physical, mechanical and bioactive properties of the films, but their performance can be affected by their composition, molar ratio and amount added to the film solution. These findings highlight the potential of DESs for the plasticization of chitosan films as a novel technology in food packaging systems. The production processes of these films should be translated at an industrial level to maximize their potential.