Acetylated Xylan as Renewable Feedstock for Biodegradable Food Packaging: Synthesis, Structural Characterization and Performance Evaluation

This study investigates the potential of acetylated xylan as a functional component in coatings for biodegradable paper-based food packaging. Acetylated xylan was synthesized in the laboratory via the reaction of native beechwood xylan with acetic anhydride. Multilayer coatings composed of acetylated xylan, chitosan, and zinc oxide nanoparticles (ZnO NPs) were applied to paper substrates as single and double layers (approximately 5 g/m2) to enhance their barrier and antimicrobial properties. The coated papers were evaluated for mechanical properties, resistance to water, oil, and grease, antimicrobial activity against pathogenic bacteria, and biodegradability in soil. The combination of xylan derivatives with chitosan significantly improved surface hydrophobicity (contact angle ~87°) and achieved complete inhibition (100%) of Staphylococcus aureus and Salmonella spp., without compromising biodegradability. Incorporation of ZnO NPs further enhanced both the barrier properties and antimicrobial efficacy, particularly against S. aureus. A high biodegradation rate (~92%) was recorded after 42 days of soil burial. These results demonstrate the suitability of xylan-based multilayer coatings as sustainable alternatives for food packaging applications.