Zinc Oxide Nanoparticles for Food Applications: From Synthesis and Functional Properties to Safety and Sustainability

Food loss and foodborne diseases are the two major challenges of global food systems. According to the World Health Organization, it is estimated that the amount of food usable yet discarded on a yearly basis is approximately 1.3 billion tons, and it is estimated that almost 600 million people are affected by foodborne diseases annually, which leads to an annual death toll of approximately 420,000 people. These are the problems that reflect the ineffectiveness of traditional food preservation methods. Zinc oxide nanoparticles (ZnO‐NPs) have received considerable attention due to their strong antimicrobial activity, which is enhanced at the nanoscale. Their crystal structure is wurtzite, their surface area is large, and their bandgap (3.37 eV) allows them to be more reactive and UV‐blocking and capable of photocatalyzing the formation of reactive oxygen species (ROS). The synthesis methods, physicochemical properties, food applications, and migration, biological fate and regulatory considerations of ZnO‐NPs are discussed in this review. ZnO‐NPs exhibit dissolution, which is dependent on pH, and a maximum of 70% of the material may dissolve in simulated intestinal fluid, potentially leading to elevated levels of intracellular Zn 2+ and reduced oxidative stress and inducing cytotoxic actions when the material is delivered in a large dose. Hence, safe use is defined as controlled dissolution, sustainable production of material, and risk‐benefit assessment.