ZnO Nanostructures in Active Antibacterial Food Packaging: Preparation Methods, Antimicrobial Mechanisms, Safety Issues, Future Prospects, and Challenges

Packaging of food products is one of the most important stages of the food supply chain. Nano-size materials for packing food substances with appropriate properties result in better packaging performance and longer food shelf-life. In this review, the application of ZnO nano-size in active packaging of foods is discussed to identify gaps in applications for food packaging and safety. First, the crystal structures and morphologies of modified ZnO nanoparticles (ZnO NPs) are presented, and their synergistic effects on antimicrobial activities are discussed. This review also provides an overview of antimicrobial packaging containing ZnO NPs with a focus on preparation methods, antimicrobial mechanisms, and recent progress in packaging applications. The generation of reactive oxygen species (ROS) is the primary antimicrobial mechanism, which can be varied depending on morphology and size. Generally, ZnO NPs can inactivate fungi or Gram-positive and Gram-negative bacteria growth, which reduce the risk of cross-contamination, thereby extending the shelf life of products. Notably, the health concerns and hazards regarding the safety and migration of ZnO NPs application are also elaborated. Unintentional migration, inhalation, skin penetration, and ingestion may result in human health hazards. Therefore, to provide safety regulations, further investigations such as case by case study are recommended.

Automated summary

Packaging of food products is a crucial stage in the food supply chain, and the use of nano-size materials, such as ZnO nanoparticles, can improve packaging performance and extend food shelf-life. This review discusses the application of ZnO nano-size in active packaging of foods, including the crystal structures, morphologies, antimicrobial mechanisms, and packaging applications. The generation of reactive oxygen species is the primary antimicrobial mechanism of ZnO NPs, which can inhibit the growth of fungi and bacteria and reduce cross-contamination risks. The potential health concerns and hazards of ZnO NPs application, such as migration and ingestion, are also elaborated, emphasizing the need for further safety regulations and case studies.