Gas-phase photocatalytic oxidation of ethylene with TiO2-coated packaging film for horticultural products.

摘要

Titanium dioxide (TiO2)-coated food packaging film prepared using a colloidal suspension was examined for its catalytic properties towards the photodegradation of ethylene, a primary contaminant in the package atmosphere. TiO2 suspensions were coated onto the surface of oriented-polypropylene film (OPP) using a bar coater and dried in air; the resulting film had a milky-whitish appearance. Ethylene decomposition rate increased as TiO2 particle size decreased. Results showed that TiO2 nanoparticles offered a larger surface area for adsorption and decomposition of ethylene and higher UV light absorption than TiO2 microparticles. Using TiO2 nanoparticles, ethylene decomposition increased as the TiO2 concn. 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% TiO2 nanoparticle coated film. Application of 10% TiO2 nanoparticle coated film on the photodecomposition of ethylene in the packaging headspace of tomatoes was also tested. Reduction of ethylene in the package atmosphere achieved by TiO2-coated film was 88 +or- 6% using black light lamps, while a reduction of 76 +or- 10% was achieved using fluorescent light lamps. Results suggest that the TiO2-coated film can be used as ethylene scavenger packaging for horticultural products.