From the moment that delicious loaf of crispy, hot bread leaves the oven, it interacts with microbes, fungi and yeast in the air—and a few days later, lumps of bluish-green mould appear on its surface.
That's why packaged bread contains preservatives to extend the shelf life of the product. But Brazilian researchers have found a way to reduce the amount of chemicals put into bread while making it last longer.
Called 'active packaging', this alternative adds natural preservatives to the packing material instead of chemicals to the fresh bread. The compounds used in active packaging come from plants such as oregano and clove, which have natural antimicrobial properties.
The team of scientists from the University of Viscosa in Brazil have mixed plants’ essential oils with water, and a thickener derived from plant material and used them to make ‘edible films'.
The edible films are placed inside the plastic bags used to store bread, and the researchers have found that bread remains mould-free for 15 days at room temperature.
The results of their studies were published in the Journal of Agricultural and Food Chemistry.
The researchers also placed small sachets with oregano essential oils into the bread packaging. In this experiment, they opened the package every five days to test their effectiveness, and found similar results.
The team explained to Business Insider that "these techniques could be used on a larger scale, on different types of bread. For example, the edible films are great for vacuum-packed food, where the sachets wouldn’t work." Now they are applying these films to fruits, meat products, and dairy products to see if they get the same results.