Modification of physicochemical, antioxidant, and antibacterial properties of chitosan film with curcumin-loaded TA/Fe nanoparticles

The aim of this study is to fabricate novel chitosan-based film loaded with curcumin loaded metal-phenolic nanoparticles (MPN@Cur NPs) as an active agent for food preservation. The average particle size and ζ-potential of the MPN@Cur NPs were determined to be 205.9 nm and −26.8 mV, respectively. The impact of incorporating MPN@Cur NPs upon the morphology, microstructure, physicochemical characteristics, and functional activities of CS-based films were investigated through scanning electron microscope, infrared spectrometer, X-ray diffractometer, ultraviolet spectrometer, antioxidant activity and antibacterial activity analysis. The outcomes indicated that MPN@Cur NPs exhibited good mechanical compatibility with chitosan, effectively filling voids within the film matrix and significantly enhancing its mechanical characteristics (e.g., elongation at break improved from 22.6% to 37.3%; tensile strength improved from 31.1 MPa to 43.6 MPa). Additionally, films incorporating MPN@Cur NPs displayed superior barrier properties (e.g., water vapor and oxygen transmission), enhanced thermal stability, and improved UV-blocking capabilities compared to pure CS films (transmittance for UV decreased from 93.6% to 35.3%). Moreover, these films exhibited a marked increase in antibacterial efficacy against the foodborne pathogens Staphylococcus aureus and Escherichia coli, as well as elevated antioxidant activity (e.g., scavenging capability for DPPH increased from 9.22% to 85.19%, ABTS increased from 8.62% to 80.02%). Ultimately, the CS-based film significantly prolonged the shelf life of milk stored at 25 °C. Therefore, nanocomposite films provide an attractive and promising pathway for the high value-added commercial use of chitosan in food conservation.