New methods reduce the water footprint of food production

The production of fresh vegetables and fruits around the world consumes significant amounts of water and utilises chemicals to ensure preservation. For example, lettuce producers in Southern Europe use two kilograms of water to rinse a single kilogram of lettuce.

Lappeenranta University of Technology (LUT) has launched the international CEREAL research project, which is developing a water cleaning process aimed at reducing water use in the production of fresh produce by at least 50%.

As the world population increases, the number of areas where the amount of clean water available is too small in relation to population is constantly increasing. Professor Mika Mänttäri and Post Doctoral Researcher Mari Kallioinen, who are responsible for CEREAL project research at LUT, estimate that fees for clean water may already increase significantly in the near future. This is why the use of clean water in food production also has to be clearly reduced.

Aim is a sustainable and cost-effective purification

The CEREAL project is developing a separation and cleaning process based on membrane technology and oxidisation. A membrane is a thin coating that contains small pores. These pores allow water to pass through but block contaminants that end up in the water when vegetables are rinsed. An oxidisation method based on an electric discharge can be used to break the contaminants down into hydrogen and carbon dioxide.

According to Mänttäri, this combination of technologies helps to provide sufficient water quality in places where vegetables and other fresh produce are rinsed. The goal is to reduce water use in the food industry by cleaning and re-using the rinsing water. The key question is how to make the water clean enough that it can be used again.

In addition to the water cleaning process, new packaging materials are also being developed in the CEREAL project. This part of the project aims at rinsing vegetables with water cleaned by means of the new process and then using new materials to pack the products, thus increasing their current shelf life without resorting to chemical treatment.

The main objective of the project is to reduce the water footprint of food production and decrease the amount of waste resulting from food spoilage on store shelves. According to the researchers, they want to reach this target by means of sustainable methods that are also cost-effective.

"The process that we are developing has to be a sustainable solution that can be implemented at a reasonable cost so that the producer's costs don't increase," says Mänttäri.

Clean water will be a huge challenge in the future

Water use in food production is a critical question in large Southern European cultivation countries. These areas also use disinfection chemicals in conjunction with rinsing and packing to prevent microbe problems that shorten shelf life. LUT is studying whether implementing a cleaning process for rinsing water could reduce the amount of disinfection chemicals needed.

However, the use of clean water in food production is not only a problem in Southern Europe. Water is also used to rinse fresh produce in Finland.

"This is also our problem. We eat Spanish tomatoes, meaning that as end users we also contribute to water consumption at the beginning of the chain," states Kallioinen.

The CEREAL (Improved resource efficiency throughout the post-harvest chain of fresh-cut fruits and vegetables) research project is part of the EU-funded SUSFOOD ERA-NET programme. The research is being conducted as European cooperation involving eight universities and research institutions around Europe. The project will last for three years, and Professor Mika Mänttäri from the Laboratory of Separation Technology and Post Doctoral Researcher Mari Kallioinen are responsible for its implementation at LUT. 


Further information:

Mika Mänttäri, mika.mänttä, +358 40 734 2192.

Mari Kallioinen,, +358 40 593 9881.