Wrapping bread in edible films infused with essential oils could keep the staple fresher.Image credit: Klaus Höpfner, Wikimedia CommonsA study from the American Chemical Society’s Journal of Agricultural and Food Chemistry reports the development of new edible films containing oils from clove and oregano that preserve bread longer than commercial additives.

Nilda de F. F. Soares and colleagues note that the search for new ways to keep packaged food from spoiling has led some scientists to essential oils, which can keep bacteria and mold at bay. Oils from clove and oregano had already been incorporated into edible films. But scientists still needed to optimize the effectiveness of these films and test them under real-life conditions for other uses. So Soares’s team decided to test how well different edible films with clove and oregano essential oils could maintain bread’s freshness and see how they measured up against a commercial antimicrobial agent. Bread is a common staple around the world and is often kept fresh with calcium propionate. Though naturally occurring, some research suggesting negative side effects have tarnished its popularity.

The scientists bought preservative-free bread and placed slices in plastic bags with or without essential oil-infused edible films. To some slices, they added a commercial preservative containing calcium propionate. After 10 days, the latter additive lost its effectiveness, but the edible films made with small droplets of the oils continued to slow mold growth.

The authors acknowledge funding from the National Council for Scientific and Technological Development.