Nanotechnology – packaging food for the future
With forecasts that the world’s population is set to reach 9.6 billion by 2050, issues related to food are becoming increasingly important. One such issue is the challenge to find more sustainable and environmentally friendly alternatives to food packaging. This is vital to make food last as long as possible to maintain an adequate food supply.
Photo by: Su-Lin
For this reason there is considerable excitement about new developments in the field of material sciences. Recent advances in nanotechnology, and antimicrobial substances are paving the way for a revolution in the packaging industry.
Nanotechnology has tried to resolve two important problems with food packaging: how to signal that a product has gone off, and how to prevent this in the first place. This has meant a sharp focus on how to keep food in an oxygen-free environment, as oxidation is one of the main factors affecting shelf life and microbiological spoilage. Nanomaterials can also be used to reduce the effect of other harmful factors, such as UV-rays, moisture and light.
Although scientists have been able to create an oxygen-free atmosphere by using materials such as flexible plastics, they face challenges when using metals and glass, which though impermeable to gases, reduce the flexibility of the packaging and also raise costs. Here, nanotechnology may offer a solution, as a coating just a few nanometres thick is sufficient to create an impermeable layer. Materials such as polyolefin, metal film, polyamide and polyester can be used to create impermeable layers which prolong the shelf life of the product and ensure the product is safe for consumers.
In addition, researchers have developed sensors based on nanoparticles, which change colour in response to changing acidity levels. In the future, these particles could also be used to release preservatives when the product goes off. This concept has already been tested at The Chinese University of Hong Kong, where researchers developed a method using plasmonic nanocrystals to construct time–temperature indicators that signal when a carton of milk had gone off. The experiment was promising since the materials were low in toxicity and also relatively affordable.
Other applications of nanotechnology include producing biodegradable and, eventually, edible packaging. This would revolutionize the way food is produced, stored and consumed world-wide.
Emma Davies is a Millennium Youth Camp alumna, studying microbiology at the University of Helsinki.