▎ 摘 要
Oxygen is crucial to food preservation and food spoilage. For the purpose of monitoring the integrity of modified atmosphere packaging (MAP) by nondestructive testing and controlling the reaction rate during recovery stage, we reported on a convenient and visual colorimetric oxygen indicator based on a graphene/titanium oxide composite, incorporating glycerol, methylene blue (MB), hydroxyethyl cellulose, and polyvinyl alcohol. The graphene/titanium oxide composite was synthesized from a modified Hummers synthesis of graphene oxide, followed by the hydro-thermal treatment with butyl titanate without using any reducing agent, then the morphology and structure characteristics were analysed by X-ray diffraction, Fourier transform infrared, Raman spectra, ultraviolet-visible spectroscopy, SEM, and TEM. Supported by the performance tests using ultraviolet-visible spectroscopy and CIElab, the indicator demonstrated the pseudo first-order kinetics of MB for MAP in detecting stage. The results confirmed that the prepared colorimetric indicator could actually detect the integrity of MAP without destruction. Additionally, the reaction time of indicator in recovery stage can be controlled by changing the concentration of MB because of pseudo first-order kinetics.