Could ‘hot baths’ cut vegetable waste?

According to the research team, from Aarhus University, current industry techniques to clean root vegetables before they are distributed could actually reduce shelf life.

Most root vegetables are washed and brushed before being sent to supermarkets. However, this procedure wounds the vegetables leaving scratches that provide easy access for bacteria and fungi, researchers from the Department of Food Science at Aarhus University believe.

A new research project, KvaliRod, has been launched to investigate methods of increasing shelf life. The project will run until 2021 and the University is working in cooperation with two Danish companies: Gl. Estrup Gartneri and Limfjords Danske Rodfrugter.

“This is the first time that we thoroughly examine the washing process in order to optimise it and hopefully give root vegetables a longer shelf life,”​ explained Merete Edelenbos, Associate Professor at AU and the project manager of KvaliRod.

Hot water hypothesis

The researchers believe that washing the vegetables in hot water instead of cold may actually stimulate the root vegetables’ natural defences against factors that cause them to go off.

“When root vegetables are rinsed in hot water, their inherent defence mechanisms are activated, making the vegetables more resistant towards infections,”​ Edelenbos explained.

The addition of essential oils with antimicrobial properties to the water they are washed in may offer a further defence. The research project plans to initially experiment with thyme and oregano oils.

“We Will investigate if we are able to able to reduce the number of specific microorganisms by the treatments, how the treatments impact the sensory and chemical profiles and if treatments improve shelf life,”​ Edelenbos told FoodNavigator.

Food waste and exports

If the project proves successful it has the potential to reduce food waste and deliver a competitive advantage to the Danish root vegetable industry.

“We hope to be able to increase the shelf life of root vegetables with as much as two weeks. This means a 5% reduction of food waste at retail, and 30% at the consumer [level],”​ said Edelenbos.

Danish root crop producers are primarily suppliers to retail businesses in Denmark as well as neighbouring countries but longer shelf life could open up new export opportunities.

“The organic market in China, for instance, holds significant potential, but so far, it has been out of our reach because of the reduced shelf life. We hope that the project will allow root crop producers to enter new markets,”​ Edelenbos said.

The KvaliRod project is under the Green Development and Demonstration Programme and has a duration of four years. “We will need several seasons and we will need to upscale if the technology works,”​ Edelenbos concluded.