Green halochromic smart and active packaging materials based on chitosan film loading nanoparticles: Functionality, physicochemical properties and application

Despite extensive commercial and regulatory interventions, food spoilage and plastic packaging contamination continue to have large ramifications on human health and the global economy. Intelligent active packaging that can both monitor food freshness in real-time and improve food quality is needed. In this study, curcumin-zein- quercetin-chondroitin sulfate nanoparticles (CZQC NPs) with ammonia/acetic acid sensitivity and antioxidant activity were prepared and then loaded within a chitosan film to give a smart film. The effect of NPs loading upon the structure and physicochemical characteristics of the chitosan based films were studied. The scanning electron microscopy confirmed that the NPs had good compatibility with chitosan and filled the void in the film matrix. The NPs were uniformly integrated inside the chitosan film, which significantly improved its mechanical properties (tensile strength from 26 to 62 MPa; elongation at break from 35 to 61%), oxygen and water barriers and ultraviolet light protection. The NPs films showed significant antibacterial efficacy, antioxidant activity and a beneficial ammonia/acetic acid/pH-sensitivity. Thus, the NPs composite film could sensitively detect fillets freshness with discernible color changes. Therefore, the NPs composite films may potentially be applied to indicate and extend the freshness of packaged foods.