Chapter 9 - Zinc oxide nanomaterials as antimicrobial agents for food applications

Abstract

Many metallic NPs, such as silver, copper, zinc, and gold NPs, have been used in food products as preservative packaging material. Zinc oxide (ZnO) NPs are generally recognized as safe (GRAS) by the US FDA and are effective against many microbes. ZnO NPs not only have antimicrobial properties but also support the activity of other antibiotics, such as vancomycin and others. ZnO NPs can be prepared by a mechanochemical process or physical vapor synthesis. The size of the NPs depends on the method used: in mechanochemical processes the size of the NPs is 20–30nm, whereas it is 8–75nm in physical vapor synthesis. ZnO NPs have been used as preservatives in food packaging materials. The exact antimicrobial mechanism of ZnO NPs is not well known; however, it has been theorized that ZnO NPs lyse the cell wall of microbes. The antimicrobial potential, GRAS status, and nutritional importance as a source of zinc nutrient have encouraged the use of ZnO NPs in food and feed applications.