The approach uses plasma processed air applied with a microwave torch for wet and dry applications. Research began in 2012 and is scheduled to continue until September this year.
Dr Jörg Ehlbeck, head of the plasma bioengineering department at the Leibniz Institute for Plasma Science and Technology, said the technique could be tested on industrial-sized crates of vegetables from the end of April. He was speaking at the Anuga FoodTec 2015 trade show in Cologne.
Pilot system
“We can treat boxes and trays, which are used in the industry, at the size our [commercial] partners use,” he told FoodManufacture.co.uk. The pilot system would be able to handle 600mm x 400mm x 240mm crates, he said.
“We will then have to develop the software. The project is running until September and the focus will be on upscaling the system. We are looking forward to showing some promising results from then. The next step will be to go closer to a prototype.”
The research team were aiming to build a cost-effective system tailored to the production processes of their industrial partners, said Ehlbeck. “The efficiency will depend on the kind of vegetable, the amount of dirt and so on.”
Effects on quality
Another aspect that needed to be addressed was whether the treatment would have negative effects on the quality of the vegetables, with some varieties likely to be more sensitive than others, he said. Tests so far had shown negligible detrimental effects, he claimed.
Any workable system would have to be designed according to regulations with the help of commercial partners, he added.
Depending on the length of time products were treated, the system could achieve reductions of, for example, five or six logs in the case of E.coli contamination, Ehlbeck said. That meant the number of microorganisms on a product could be reduced by up to one million-fold.