Reducing vegetable production can make food more durable

Every year, large quantities of vegetables and mushrooms are wasted during production before they reach the shelves. The 'PlanteFerm' project aims to reduce this waste by giving it new life. In the project, the Technical University, together with Tvedemose Ingredients, has investigated whether side streams from vegetable and mushroom production can be fermented and used as natural preservatives in entirely different foods. The preliminary results suggest that what previously ended up as waste can become functional ingredients, while food producers gain a natural tool to extend shelf life and enhance food safety in their products. "We can now document that fermented side streams actually work against some of the bacteria that concern food producers the most. This opens up real potential to make plant-based products more durable without resorting to chemical preservatives," says Anette Granly Koch, Ph.D. and professional leader at the Technical University, in a press release. Hindering dangerous bacteria In laboratory tests of the project, a range of fermented vegetables and mushrooms have been examined for their ability to inhibit bacteria such as Bacillus cereus, a bacteria that can cause food poisoning; Clostridium botulinum, which can cause the severe poisoning botulism; and Listeria monocytogenes, known as the listeria bacteria. Fermented mushrooms proved particularly effective against Bacillus cereus in stews, while the effect on Clostridium botulinum varied, and the researchers therefore point out that further optimization is needed before the method can be widely used against that bacteria. Fermented carrots also showed an inhibitory effect against listeria bacteria and could simultaneously slow the growth of the natural background flora in coleslaw. Through the fermentation process, microorganisms convert the natural sugars in vegetables into substances such as lactic acid, which lowers the pH and makes the environment acidic and thus unattractive for spoilage and disease-causing bacteria. The project has also examined how much of the fermented vegetable product, called a fermentate, can be added to a food without affecting taste, quality, or the economics of production. The results indicate a dual potential, according to the press release: side streams from vegetable and mushroom production, which currently have limited value, can become functional ingredients, while food producers gain a natural tool to extend shelf life and improve food safety in their products.