Cross-linked chitosan-phytic acid coating for eco-friendly food packaging paper

The development of novel food packaging materials that are both eco-friendly and highly oil-resistant has been identified as a critical challenge in the food packaging industry. Herein, a facile strategy for fabricating food packaging paper with oil and water resistant properties is reported. Specifically, filter paper was used as the substrate, chitosan was employed as the film-forming matrix, and phytic acid was utilized as a crosslinking agent to modify chitosan, resulting in the successful preparation of functional paper with excellent oil and water resistance. The effects of chitosan coating concentration and phytic acid crosslinking time on the oil and water resistance were systematically investigated. The optimal oil and water resistance was achieved when the chitosan coating amount was set at 30 g/m 2 and cross-linked with a 5% wt phytic acid solution for 10 min. The material exhibited oil resistance lasting beyond 24 h and water resistance exceeding 30 min, demonstrating its ability to effectively block oil for prolonged periods and withstand water exposure, suggesting potential utility in food-contact packaging applications.