Nanotechnology | How It’s Used In Food And Packaging

If we can mitigate the potential health risks, nanotechnology offers plenty of benefits regarding food and its packaging, from boosting taste and shelf life to making food healthier.

What is nanotechnology?

Nanotechnology is the science that happens at the scale of a nanometre (nm) – that is, a billionth of a metre, or 0.000000001m. Particles that range in size between 1nm and 100nm are by definition, nanomaterials.¹ To put that figure in context, a single strand of DNA is around 2nm across.

Naturally occurring nanoparticles have been present in food for as long as we’ve been producing food to eat – casein proteins in milk, for example, are nano-sized.²

But now, scientists can manipulate materials at the nanoscale to be used in a number of new ways in food and food packaging. For example, nanomaterials can be added to food packaging to keep food fresh and reduce food waste. In food itself, nanotechnology can alter flavour or add nutrients that wouldn’t otherwise be present.³

Making food healthier – but still tasty

Playing with our food at the nanoscale could bring health benefits while retaining the tastes we already know and love.

For example, mayonnaise – made by combining oil, egg yolks, vinegar and flavourings into an emulsion – typically contains around 70% fat when made traditionally. Its texture is provided by tiny, naturally nano-sized fat droplets in the emulsion. By manipulating these droplets and filling them with water instead of fat, researchers hope to keep the thick, creamy texture of mayonnaise but reduce the overall fat content to less than 40%.⁴

Salt is another ingredient that makes food taste good but isn’t necessarily good for us. By scaling down salt crystals to the nanoscale, the salt's surface area to volume ratio is increased, meaning food manufacturers can use less salt to achieve the same flavour boost.⁵

Nanotechnology and food packaging – Keeping food fresh for longer

Packaging is also an area where nanotechnology could make a significant impact.

For example, beer manufacturers in the US are already using nanoparticles of clay in plastic bottles to keep beer fizzy for longer. The tiny flakes of clay fill in the minuscule holes left between the larger plastic molecules, meaning less gas can escape through the walls of the bottles, helping the drinks keep their carbonation over a longer period of time.⁵

Silver nanoparticles are already widely used in a number of applications, including food packaging, as a way to kill harmful bacteria because of their antimicrobial properties.²

Going one step further than just keeping food fresh, nanotechnology could also be used in intelligent packaging to indicate whether food is still good to eat. Researchers are exploring the idea of using carbon nanotubes in food packaging to create a sensor that could tell you whether the food was still fresh by detecting gases that are released when food spoils. The carbon nanotubes would be sprayed onto flexible plastic film used in the food packaging.⁶

The risks of nanomaterials in food

Because nanomaterials often have properties different from those same materials at a normal scale, there are a number of potential risks that make investigating the full impact of nanomaterials in food especially important. Many nanomaterials can be small enough to penetrate tissues in our bodies more easily than their regular-sized counterparts. There are still gaps in our knowledge of the potential health effects of nanomaterials in some food applications.

It’s possible that silver nanoparticles, for example, could migrate from food packaging and end up ingested with the food itself. We don’t yet have a clear idea of the toxic effects they could have on humans when entering the body with food, but the intestinal tract and liver are considered particularly vulnerable. Research has also shown that when silver nanoparticles enter cells, they can cause inflammation and provoke what’s known as oxidative stress, caused by an imbalance of antioxidants and free radicals, leading to free radicals causing damage to cells.⁷

In Europe, regulations around using nanomaterials in food have been built into existing food and packaging regulations. Since 2014, prepacked food containing engineered nanomaterials must be labelled as such.⁸ Have you ever noticed one of these warnings on your food?