Putting a spark into food preservation

SAFEBAG:WE'VE ALL BEEN there: bought some perfectly good-looking fresh fruit or vegetables only to find that within a couple of days the food has gone off.

A new project called Safebag is developing a technology to help keep fruit and vegetables fresher for longer by inactivating microbes on the food, explains Dr PJ Cullen, a lecturer at Dublin Institute of Technology’s School of Food Science and Environmental Health, who is involved with the €2.4 million EU-funded project.

“It’s difficult to treat fresh produce in comparison to things like milk where you can use pasteurisation and heat,” says Dr Cullen. “The classical approach has been to wash the produce and what’s typically done is that it is washed in chlorine.”

But the Safebag project is looking to develop an alternative that uses plasma to treat the produce within the package.

“The idea is that we simply package our food inside any type of plastic packaging, then we pass that package through a dielectric discharge, which is essentially two electrodes of high voltage,” explains Dr Cullen. “So we create and use a plasma within the bag for a very short period of time, and we make active species within the bag, which inactivate the bacteria. And then convert after a period back into the original gas.”

The goal is to reduce microbial hitchhikers on fresh produce that could ultimately contribute to spoilage, explains Cullen, but the project also wants to ensure that the technology does not negatively affect the nutritional properties or the taste of the fruit and vegetables themselves.

The EU-funded project, which is developing a pre-competitive prototype and validating the technology involves DIT, Jean-Paul Mosnier in Dublin City University at the National Centre for Plasma Science and Technology as well Irish food company Nature’s Best Ltd and other international partners.