The use of cold atmospheric plasmas to inactivate Salmonella has recently been reviewed by researchers from the Institute of Food Research.

A growing demand for fresh produce means the food industry is under constant pressure to supply safe food with minimal processing. And it’s crucial that these foods are supplied without microbial contamination as many of them are eaten raw. As a result, there has been much interest in novel ways of preserving food and destroying microorganisms without affecting quality.

One such emerging technology is the use of cold atmospheric plasma (CAP) treatment, and a recent review by IFR microbiologists has summarised what is known about how Salmonella is inactivated by CAP – and suggests what further research is needed before it can be integrated into the food supply chain.

Plasmas are created when gases are excited by externally applied energy sources, and they consist of a variety of highly energetic particles, which in combination are able to inactivate microorganisms. However, how this is done is not fully understood.

IFR scientists Dr Arthur Thompson and Dr Ana Fernández have published research on the subject and concluded that CAP treatment can be highly efficient at inactivating Salmonella, killing cells in a very short period of time.

Now, funded by the European Union, Fernández is looking at the genes that are activated when Salmonella survives the treatment. By looking at the changes in gene expression, it will be possible to identify which cellular processes are employed by Salmonella. Knowledge of these processes can then be used to optimise the CAP treatment technique to prevent the resuscitation, so refining the technique and helping to ensure that food is free of microbial contamination, says IFR.