A new approach to develop biodegradable films based on thermoplastic pectin

Pectin, a natural and renewable polysaccharide (used in the food industry as stabilizer, thickening and encapsulating agent), is considered a polymer with great potential for future developments. However, due to the poor mechanical and barrier properties of neat pectin-based films, the application in food packaging is highly limited. In this work, we report, for the first time, the successful fabrication, by thermo-compression molding, of pectin films with natural deep eutectic solvent (NADES - ChCl:Gly (1:2)) or its individual components (glycerol (Gly) and choline chloride (ChCl)), as plasticizers. The impact of thermo-compression molding parameters and the effect of plasticizers on mechanical, optical, water resistance and morphological properties of the films were studied. Pectin thermoplastic formulations were significantly affected by changing the plasticizer, its quantity and the time of compression. Films were yellowish, visually homogenous, semi-transparent, without pores or cracks. A decrease in the compression time seemed to decrease the roughness of the films. The pectin/glycerol films presented higher tensile strength values than films containing NADES or ChCl plasticizers. An increase of water resistance values in pectin/Gly films was observed upon use of NADES and ChCl plasticizers.