Empa and Lidl Switzerland have jointly developed a cellulose protective coating to food waste reduction. For fruit and vegetables. The novel coating has made from so-called pomace. – Squeezed fruit and vegetable peels. The innovative project can reduce packaging and prevent food waste.
Ecological coating for Bananas
Plastic packaging in grocery stores protects fruits and vegetables from spoilage. But also creates significant amounts of waste. Together with the retailer Lidl Switzerland, Empa researchers have now developed a protective cover for fruit and vegetables. Based on renewable raw materials. For this project, Lidl chose Empa as a partner because Empa had decades of research experience with cellulose products.
Keeping fruits fresh at home
In Empa’s Cellulose & Wood Materials laboratory, the researchers then spent more than a year developing a special protective cellulose coating that can be applied to fruits and vegetables. The result: coated fruits and vegetables stay fresh significantly longer. In tests, the shelf life of, for instance, bananas has extended by more than a week. This significantly reduction of food waste. “The big goal is that such bio-coatings will be able to replace a lot of petroleum-based packaging in the future”. Says Gustav Nyström, head of the Empa lab.
Production from residues
The idea is to process so-called pomace into fibrillated cellulose. Pomace is the solid residue left over after extracting the juice from fruit, vegetables or plants. Previously, this plant leftover has disposed of in biogas plants or directly on the field. In the future, it will used to create a protective coating for fresh fruit. The coating has either sprayed onto the fruit or applied to the produce as a dip and is easy to wash off. As it is harmless to the consumer, it can also be consumed without harm. The potential of cellulose coatings is by no means exploited yet. There is the possibility of adding additives such as vitamins or antioxidants.
To wrap or not to wrap?
Plastic packaging waste is an immense problem for the environment. Retailers are therefore looking for ways to do without plastic packaging for food. However, not all fresh vegetables and fruits are provided by nature with a suitable protective cover that suits our cooling and storage conditions. Oranges and lemons may be so comfortable in the home refrigerator without a plastic cover that they last for weeks. Not so the cucumber! The dry air in the refrigerator does not agree with it, it becomes rubbery and possibly ends up in the trash. If, on the other hand, it has wrapped in a plastic cover, it stays crisp for longer. So a thin layer of plastic maybe means food waste reduction.
How ecological are plastic wrappers for cucumbers?
Researchers at Empa in St. Gallen have now used life cycle assessment analyses. To calculate how food waste due to spoiled food can offset against the environmental impact of plastic packaging on imported cucumbers. For the model calculation, they followed the path of a cucumber from the producer in Spain to a Swiss supermarket. According to this, the plastic wrapping accounts for only 1% of the environmental impact caused by production and transport. Overall, the positive effect on the environment from less “food waste” is almost 5 times higher than the negative effect from packaging, according to the researchers.
(source: Empa)
