According to WWF, food waste accounts for around 10% of global greenhouse gas emissions. About 40% of all of the food produced worldwide is lost or wasted along the value chain. And Austria generates one Million tonnes of avoidable food waste every year, although there is a lack of reliable data for the agriculture sector. More than enough reasons, then, to carry out a detailed analysis of ways to reduce food waste – which is the focus of researchers on the Austrian Research Promotion Agency’s (FFG) LED4foods project.
Light and shelf life
Coordinated by the JOANNEUM RESEARCH MATERIALS Institute in Pinkafeld, LED4foods is examining the effects of specifically directed LED lighting in supermarkets on the shelf life of fresh products. The idea was proposed by Burgenland-based company Lumitech Lighting Solution GmbH, which has previously developed lighting solutions for fresh and cured meat display cabinets. This expertise is now being applied to perishable fruit and vegetable varieties. "Until now, research has mainly investigated the effect of light on foodstuffs during storage and transportation, but hardly any attention has been paid to its application in supermarkets," explains Christian Krutzler, the project manager at JOANNEUM RESEARCH. The goal is to slow microbial and ageing processes using particular wavelengths of light, because wilted greens and shrivelled produce are unappealing to shoppers.
Less microorganisms
Krutzler is working with a team from the TU Graz Institute of Analytical Chemistry and Food Chemistry as well as Lumitech Lighting Solution GmbH to find out what effects light of different colours has on foods including radishes, bananas and tomatoes. One particularly promising approach is the use of blue light, which initial findings suggest could Limit the growth of microorganisms. "And this removes the health risks that can occur with UV-C irradiation," says Krutzler of the encouraging results. The Researchers devised a set-up and corresponding methodology in order to record the effect of different spectral light distributions on the ageing and spoilage of fruit and vegetables under controlled conditions.
In focus: Fruit and vegetables
This involved setting up lighting where the spectral intensity distribution from 12 different LED components can be combined and adjusted over wide ranges, and adapted in line with the desired distribution. In Addition to the usual wavelengths in the visible spectrum, the 12 LED components also included two LEDs in the UVA spectrum (at 385nm and 395nm) and two in the deep red and near-IR spectrum, at 660nm and 730nm respectively. This approach enables the reproducible analysis of different spectral distributions in a series of controlled tests, as well as recording of the effects of each distribution on established quality Parameters for fruit and vegetables, including loss of mass and changes in colour. This research breakthrough could deliver significant advantages for retailers as well as the environment, as the lighting technology can be installed without the need for major renovations. "The lighting concept could be deployed immediately – but, of course, it depends on whether the retail chains get on board," Krutzler comments. "In terms of practical implementation, the challenge is ensuring that the products remain visually appealing."
