Gas-Phase Photocatalytic Oxidation of Ethylene with TiO 2 -Coated Packaging Film for Horticultural Products

摘要

Titanium dioxide (TiO 2 )-coated food packaging film prepared by using colloidal suspension was examined for its catalytic properties towards the photodegradation of ethylene, a primary contaminant in the package atmosphere. The TiO 2 suspensions were coated onto the surface of oriented-polypropylene film (OPP) using a bar coater and dried in air; the resulting film has a milky whitish appearance. The ethylene decomposition rate increased as the TiO 2 particle size was decreased. Results showed that TiO 2 nanoparticles offered a larger surface area for adsorption and decomposition of ethylene and higher UV light absorption than TiO 2 microparticles. Using TiO 2 nanoparticles, ethylene decomposition increased as the TiO 2 concentration increased from 0.1% to 10%. A Langmuir-Hinshelwood expression was used to correlate the entire set of rate data. The relative higher photocatalytic activity was obtained with the 10% TiO 2 nanoparticle coated film. The application of the 10% TiO 2 nanoparticle coated film on photodecomposition of ethylene in the packaging headspace of tomato fruits was also tested. The reduction of ethylene in the package atmosphere achieved by TiO 2 -coated film was 88% � 6% using black light lamps, while 76% � 10% reduction was achieved using fluorescent light lamps. The results suggested that the TiO 2 -coated film can be used as an ethylene scavenger packaging for horticultural products.