Dual functionality of deep eutectic solvents in chitosan-based biodegradable films for food packaging applications

Abstract

The growing demand for eco-friendly food packaging highlights the need for alternatives to synthetic polymers. This study presents a novel approach incorporating an antibacterial plant extract in a deep eutectic solvent (ExDES) into chitosan-based films. Notably, DES was used to extract bioactive compounds from tomato leaves, and the resulting extract, without separating the solvent, was directly incorporated into the films. This method provided a dual effect: DES functioned as a plasticizer, while the bioactive compounds in the extract contributed to the films antibacterial properties. Analysis of the mechanical, barrier, and antimicrobial properties of the obtained films revealed that the ExDES modified films exhibited enhanced performance, achieving the highest elongation at break (48 %) for the film with ExDES containing choline chloride, glycerol and lactic acid (ExD(CGL)). These findings demonstrate the potential of ExDES-modified chitosan films as sustainable packaging materials with improved mechanical strength and antimicrobial protection.