Pathogen inactivating plasma can lead to double shelf-life

A new method for decontaminating produce by inactivating microbes in sealed packaging has the potential to double the shelf-life of fruits and vegetables.

Researchers from the Dublin Institute of Technology (DIT), working as part of a €2.4 million EU-funded project, are developing a method of extending shelf-life by inactivating microbes on fruit and vegetables. The project, Novel continuous in-pack decontamination system for fresh fruit and vegetables, as an alternative to chlorine-based disinfection (SAFE-BAG), aims to produce a prototype in-pack decontamination system.

SAFE-BAG aims to reduce microbes on fresh produce while insuring that the technology does not affect the nutritional properties, texture or taste of the packaged fruit or vegetables.

Dry, non-thermal process

Dr PJ Cullen, a lecturer at DIT School of Food Science and Environmental Health said: “At the moment, there is no way of treating fruit and vegetables without chlorine washes or gamma rays, even processes like HPP won’t work.”

“What we want to do is develop a dry, non-thermal process of decontaminating fruit and vegetables, making produce safe to eat as well as extending its shelf life, while not affecting the texture or taste of the product.”

“The shelf-life of a treated item will vary, depending on the product itself as every type of fruit or vegetable has a different original shelf-life - but there will be a significant shelf-life extension.”

The process involves the passing of a dielectric discharge - two electrodes of high voltage electricity through food in normal food packaging lined with plasma.

Plasma, which is widely used for industrial materials and processing, has recently shown promise as a decontamination tool, by inactivating pathogenic bacteria on food contact surfaces.

This plasma creates an active species within the bag, which then inactivates pathogenic bacteria in the food package. These active species then convert back to their original composition over a period of around 12 hours.

Commercially availability

“Our goal is to develop a product that could double the shelf-life of most fruits or vegetables,” added Cullen.

“We have to proof it and validate it. Our goal is to build a technology for certain types of produce, which until now have been confined to treatment through washes or irradiation.”

The impact of the results hold benefits for consumer safety and confidence, extended shelf-life and increased demand for fresh produce, which will in turn impact on the competitiveness for fresh food processors, said the team.

Dr Cullen added that the project, which involves DIT, Jean-Paul Mosnier from Dublin City University, Kevin M Keener from Purdue University in the US, Irish food company Nature’s Best and other international partners, will be commercially available in the next 2 years.

Source: Dublin Institute of Technology