Nanotechnology has an extensive list of applications when it comes to food packaging. Yet, its use has been limited, largely in part due to the lack of research into the risks nanomaterials may present to consumers through food migration. Migration studies aside, nanomaterials in food packaging appear to have significant advantages.

Barriers: New and Improved

Nanomaterials have the potential to improve barriers in food packaging. Currently, foods are vacuum sealed using flexible plastics as barriers. However, these plastics are slightly permeable to oxygen and other gases. Over time, oxygen leaks inside the packaging which is what causes food to spoil.

Using nanomaterials, metal coatings only nanometers thick can be added to barrier films. Metal and glass are impermeable materials but their use is impractical, as they are more expensive and inflexible. In these improved barriers, the metal layer is sandwiched between layers of polyolefin, polyamide, and polyester. These new barriers inhibit the migration of water, oxygen, flavor, etc., keeping food fresher for longer.

Antimicrobial/Antibacterial Coatings

Antimicrobial food packaging not only acts as a barrier, but actively works to reduce the growth of harmful microbes. Silver nanoparticles are used to make antibacterial coatings. Zinc oxide and magnesium oxide can also be used as nanofillers. They inhibit the growth of microorganisms, thus reducing food spoilage and expanding shelf life.

Food Packaging Made Smart With Nanomaterials

Smart or intelligent packaging is even more hands on when it comes to food packaging. Nanoelectronics have the potential to control the environment inside the packaging and alert consumers of decay. Time and temperature indicators let consumers know when food has experienced an irreversible chemical change after exposure to a change in temperature. Integrity indicators monitor the gas composition of decomposing food. The tag is activated when the seal is broken and a color change occurs over time. Freshness indicators work in the form of labels that monitor the first kind of change that occurs, whether it be pH, gas composition, etc. These changes are communicated to consumers via color change as well.

Nanomaterials in packaging could not only help consumers avoid food that has been compromised, but also help consumers reduce food waste by giving them a more definite expiration date. Expiration dates are often vague guesses that air on the side of caution, encouraging consumers (who often have no base level of knowledge about food spoilage beyond what they can perceive) to throw out food before it has actually spoiled. Improved barriers would extend the shelf life in the first place, antimicrobial packaging would both extend shelf life and make food safer by fighting off bacteria, and smart packaging would give the consumer a more accurate read on the freshness of their food.

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