Assessment of chitosan/pectin-rich vegetable waste composites for the active packaging of dry foods

In line with the growing demand for green alternatives to conventional petroleum-derived plastic packaging,\r\nfully bio-based and biodegradable biocomposites were developed for this work, for the purpose of packaging dry\r\nfoods, following the principles of circular economy. Solutions of plasticized chitosan (pCS) were blended with\r\nvarying amounts of hydrolyzed orange peel (hOP) waste to produce films by casting. The hydrolytic pretreatment\r\nof orange peels enabled the creation of biocomposites containing up to 80 wt% hOP, while the formulation with\r\n70 wt% hOP had the best general performance. Chemical characterization of the developed films revealed that\r\nchitosan molecules interact electrostatically with pectin molecules in hOP. The strong interaction between\r\nchitosan and pectin molecules results in improved mechanical, barrier, and thermal properties of the composite\r\nmaterials compared to their individual components. In addition, the biocomposites exhibit improved water\r\nresistance due to their reduced water solubility compared to chitosan and hOP films. The migration of the films’\r\ncomponents in the food simulant Tenax was evaluated, and the results revealed low values, compliant with the\r\ncurrent EU regulation. However, due to the electrostatic interactions, the films lost the antimicrobial activity of\r\nthe individual components, chitosan and hOP, against E. coli and S. aureus bacteria, a property that could turn the\r\ndeveloped films into active packaging. Finally, the optical and antioxidant properties and the biodegradability in\r\nsoil of the developed films were also assayed, showing high transparency, antioxidant capacity, and fast\r\nbiodegradability, reaching 62.9% weight loss after 26 days of the experiment.