Antimicrobial and controlled release properties of nanocomposite film containing thymol and carvacrol loaded UiO-66-NH2 for active food packaging

In this work, Zirconium-based metal-organic frameworks (MOFs), UiO-66-NH2, were designed as loading carriers for thymol and carvacrol and added into chitosan to construct antimicrobial packaging films. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA) were applied to characterize the films. Besides, we analyzed the physical properties, mechanical performance, hydrophobicity, release behavior, and antimicrobial capacity of the films. It can be clearly seen that the addition of thymol and carvacrol loaded MOFs into chitosan film significantly improved the thermal stability, light barrier properties, tensile strength, and hydrophobicity. Importantly, UiO-66-NH2 restrained the release rate of thymol and carvacrol compared with pure chitosan film, which endowed efficient antimicrobial capacity against E. coli, S. aureus, and P. citrinum to chitosan films. Overall, the strategy conceived here can be a superior candidate to develop a premium antimicrobial material for active food packaging, which has potential application prospects.