Migration and characterization of nano-zinc oxide from polypropylene food containers

Abstract

Background and Objective: Zinc oxide has achieved increasing attention in an extensive range of areas, due to its strong antimicrobial effect and generally recognized as safe material listed by FDA. However, the possibility of migration from commercial products is always an issue of mutual concern when its application is food packaging. This study evaluated the migration of nano-zinc oxide from polypropylene food containers to the food-simulating solutions based on the Chinese standard. Methodology: Several experimental factors influenced zinc oxide release: Food simulant, temperature and storage time. Results: Results revealed a significant nano-zinc oxide migration into oily, acidic and aqueous simulants. The amount of zinc oxide migrated increased with storage time and temperature although, zinc oxide showed a low tendency to migrate into food simulants. Conclusion: The Zn2+ substance was quantified by inductively coupled plasma mass spectroscopy (ICP-MS) and migration was found to occur within a range of 0.15-0.56 μg L–1. Meanwhile, Scanning Electron Microscopy/Energy Dispersive Spectrometer (SEM/EDS) and Malvern Zetasizer Nano were applied to identify the existence and the morphology of nano-zinc oxide.