By Yervand Kondrahjian | Staff Writer
Food packaging plays a fundamental role in providing a physical barrier to food, protecting it from damage, such as mechanical or physical harm and microbial contamination. Also, food packaging maintains product quality. In addition to convenience and protection, food packaging also serves other purposes, such as providing information to the consumer about the contents and highlighting key details about the product.
One type of food packaging that has gained increased attention is antimicrobial packaging, particularly in cheese packaging. Antimicrobial coatings and direct packaging wrappers can effectively prevent the growth of microorganisms on the surface of contaminated food products. Many active packaging films use nanostructured metal compounds, such as silver, gold, and copper nanoparticles, with antimicrobial properties.
Although literature on the use of metal nanoparticles with antimicrobial activity in packaging rarely mentions iron nanoparticles, they are used as active ingredients in oxygen scavengers for packaging and are usually protected by patent law. Some studies suggest that nano-iron has potential bactericidal effects on E. coli, which depend on the size and specific properties of the nano-iron. The absence of oxygen can also increase the antimicrobial activity of nano-iron. Furthermore, there have been no harmful effects of iron on human organisms, as even nano-iron supplements are used to treat anemia. The beneficial effect of nano-iron on iron deficiency anemia occurs at doses of 3-6 mg/kg of body weight per day, while adverse effects occur at doses above 10-20 mg/kg of elemental iron. However, nanoparticles smaller than 54 nm are recognized as a toxicological hazard.
An example of the use of antimicrobial packaging is goat cheese wrapped in polyolefin packaging foil with PLA coating, containing up to 3% ZVI, which was stored for six weeks in refrigerated conditions. No microbial growth was observed on the inner surface of the packaging or on the surface of the product due to the presence of ZVI. Furthermore, the biodegradable nature of PLA and demonstrated antimicrobial activity of ZVI/PLA films make them a promising option for active food packaging.