Chitosan-citral coated paper: A simple and sustainable approach to eco-friendly food packaging

Abstract The search for sustainable alternatives to petroleum-based polymers in packaging has driven increasing interest in cellulose-based materials due to their eco-friendly nature. This study explores the advantages of coating cellulose-based packaging with citral-imine chitosan, focusing on its impact on mechanical properties, barrier performance, and food preservation capabilities. Results revealed a remarkable enhancement in tensile strength, with increases of up to 17% in the machine direction (MD) and 25% in the cross direction (CD) compared to uncoated paper. Notably, the coating improved bursting strength by over 50%, and folding endurance increased by 150 to 350%, indicating significant durability improvements. The incorporation of citral-imine chitosan also boosted paper hydrophobicity, achieving a water contact angle of 121.1° on the coated side and reducing the Cobb60 water absorption value to 17.9 g/m 2 , enhancing the paper’s water resistance. The effectiveness of this coated paper as food packaging was evaluated using raspberries as a model. The citral-imine chitosan coating extended the fruit’s shelf life to 7 days by delaying ripening and providing a barrier against microbial contamination. These findings highlight citral-imine chitosan coating as a cost-effective and eco-friendly strategy for developing advanced cellulose-based packaging, offering both improved performance and prolonged food preservation.