From Waste to Wrap: Pistachio Shell Powder–Reinforced Chitosan Biocomposite for Eco‐Friendly Packaging

ABSTRACT Chitosan (Cs) is a biopolymer which has exceptional biocompatibility, biodegradability and antibacterial properties. On the other hand, pistachio shell (Ps) powder is environmentally friendly, sustainable, biodegradable and non‐toxic. Therefore, the combination of these two biomaterials may lead to a biocomposite with numerous attractive properties. In this work, we report the preparation and characterization of a series of Cs/Ps biocomposites. Films of these biocomposites were prepared by solvent casting and were examined by FT‐IR, XRD, DSC, TGA, SEM and UTM analyses. Analyses were conducted to evaluate their moisture content, water vapour permeability (WVP), swelling percentage and transparency for packaging applications. The composite's mechanical properties improve the most when it is loaded with 20% Ps. The high moisture content of 14.39% observed in the pure Cs film has gone down to 10.76% in its composite film Cs/Ps 40 . The biocomposite films' WVP properties are significantly influenced by the amount of pistachio filler used. At a specified time, the pure Cs film experiences the highest swelling percentage, while the Cs/Ps 40 film experiences the least swelling percentage. It has also been observed that the thermal stability of biocomposite films gradually improves with the filler amount. The thermal stability of the biocomposite film Cs/Ps 40 was higher than that of any prepared films. The evaluated properties of these films indicate that these biocomposites have the potential to be used in food packaging.