Emerging Trends for ZnO Nanoparticles and Their Applications in Food Packaging

Zinc oxide (ZnO) nanoparticles (NPs), which are declared as generally recognized as safe by the U.S. Food and Drug Administration, is discussed in this review to reveal their beneficial characteristics when incorporated into packaging matrixes for food packaging and preservation applications. Some of the major challenges in conventional packaging include microbial contamination, oxidation, moisture, gas, and UV transmission into the food, and lack of mechanical strength. These factors lead to poor shelf life, affect food quality, and cause food wastage. Advancement in packaging has shifted the focus toward nanotechnology. Nanotechnology is oriented toward the fabrication and application of materials with nanosized dimensions. Among various nanomaterials, current research has focused on ZnO NPs due to their properties and future applications. Incorporation of ZnO NPs into biopolymer packaging materials considerably enhanced the antimicrobial activity against foodborne pathogens and prolonged the shelf life of foodstuffs by a Trojan-horse strategy and reactive oxygen mechanism. Besides antimicrobial activity, ZnO NPs allow improvement of the antioxidant activity of the packaging materials by limiting the presence of oxygen in the headspace. Comprehensive ZnO nanocomposite (NC) biopolymer (BP) packaging features and their significance for food packaging applications are presented in this review. Furthermore, it discusses the effect of ZnO NPs on mechanical strength and barrier properties such as water vapor permeability, oxygen transmission rate, and UV transmission across the packaging material.