From neon lights to the laboratory: how cold plasma reduces microorganisms and food waste
Well… sort of, although they do have one important thing in common: both phenomena are related to plasma.
So, what exactly is plasma? It is the fourth state of matter, apart from the ones we already know: solid, liquid and gas. It is similar to the gaseous state, but goes a step further, because the particles in plasma are ionised, that is to say, electrically charged. We achieve the transition from gas to plasma by applying energy to the gas. If the energy applied is in the form of heat, we get thermal plasma, and if it is via another energy source, such as electricity, then the plasma will be cold or non-thermal, reaching a much lower temperature than the former.
Although it might sound a bit far-fetched, I’m sure you’ve played with a plasma sphere like the one in the picture at a science museum at some point.
And… how does this apply in the laboratory? Excellent question! As we mentioned, plasma is made up of electrically charged particles: reactive species, which vary depending on the gas that has been ionised into plasma. In the case of air, the reactive species will be nitrogen and oxygen, known as RONS. As they are electrically charged, they are capable of reacting with their surroundings, changing their properties. For example, if we apply them to a surface, we can modify it to make it more water-repellent or water-attracting.
However, one of the most interesting applications of plasma lies in its ability to decontaminate. Reactive species can ‘attack’ microorganisms and enzymes, thereby reducing the microbial load in a wide range of settings—from surfaces and utensils to entire environments—and preventing, amongst other things, cross-contamination.
As well as being easy to apply, it offers other advantages, such as leaving no toxic residues, as the reactive species recombine after a short period of time, reverting to their original gaseous state.
This opens up a wide range of possibilities for inactivating spoilage microorganisms—and, in some cases, pathogens—that cause food to spoil by producing unpleasant odours and tastes or causing discolouration. In this way, we help to improve food safety, extend the shelf life of products and, in doing so, reduce food waste.
Although plasma may seem like something straight out of science fiction, it is a promising tool for improving food safety and reducing food waste. At CARTIF’s Food Area, we are working precisely to promote this kind of innovative technology, which contributes to a safer, more efficient and more sustainable agri-food industry.
More about food…
