Metal oxide-based nanocomposites in food packaging: Applications, migration, and regulations

Background: Most nanotechnology applications for food packaging involve the use of silver nanoparticles or nanoclay. However, other nanomaterials can also be incorporated into packaging. Metal oxide nanoparticles have been added to petroleum-based and biopolymers to produce nanocomposites with enhanced mechanical and barrier properties, and their antimicrobial effects have also been reported. However, migration of nanoparticles from packaging is of concern because of their potential toxicity in the human body and the environment. Scope and approach: This review focuses on the application of metal oxide-based nanoparticles for producing nanocomposites. Advantages of incorporating metal oxide-based nanoparticles into polymers are presented, and migration of these nanomaterials from packaging into foods is discussed. Furthermore, an overview of the regulations for nanomaterials in packaging is presented. Key findings and conclusions: Addition of metal oxide nanoparticles into polymers allows for the production of nanocomposites with increased mechanical strength and water and oxygen barrier properties, and can also confer other benefits including antimicrobial activity and light-blocking properties. Migration studies have demonstrated that only a negligible amount of nanomaterial migrates from packaging into food simulants or foods, suggesting that consumer exposure to these nanomaterials and its associated health risks would be low. However, the regulatory framework for nanomaterials in packaging is still underdeveloped even in major economies.