For years, plastic packaging has been a concern of green conscious food manufacturers and consumers alike. The benefits of plastic wrapping are that it offers a cheap and effective way to protect grocery store bought food products like meats, bread, cheeses and various snacks from spoilage and foreign bacteria. But there are significant downsides that scientists are trying to offer solutions to. For example, plastic wrapping fills up landfills and oceans with non-biodegradable, long lingering plastic waste. Discarded plastic waste not only harms the environment, but it poses a threat to wildlife as well. Further, thin plastic wrapping, while generally effective, isn’t a fool proof of preventing spoilage. Some plastic films are even believed to have leached compounds into foods that could be harmful to consumers. But there are some new alternatives on the horizon, and their main ingredient might surprise you.
In the past alternatives have been tried. Biodegradable wrapping options made from chitosan or essential oils have been looked at as alternatives. But now research from the US Department of Agriculture has shown that casein, could be an intriguing alternative. What is casein? Casein is a film made from milk protein, and it holds several advantages over its petroleum-based alternative.
Says research leader Peggy Tomasula, D.SC “The protein-based films are powerful oxygen blockers that help prevent food spoilage. When used in packaging, they could prevent food waste during distribution along the food chain.”
How much more effective are milk protein derived films at keeping food fresh? According to the USDA study, casein-based films are 500 times more efficient at protecting foods from oxygen than plastic wrapping. Compared to other commercially available biodegradable food wraps, such as starch-based packaging, casein has significantly fewer microholes, making it less porous and susceptible to allowing in oxygen. Researchers learned, however, that this alone doesn’t make for a decent plastic substitute.
While the researchers quickly noticed casein’s oxygen blocking capability, it’s durability was initially an area of concern. For example, it would dissolve in water, generally not a good trait for food packaging materials. Undeterred, the scientists at the USDA study tried adding citrus pectin into the formula, which improved not only the strength but also resistance to humidity and high temperatures.
Another intriguing twist on casein packaging; it’s edible. While the concept of eating food wrappers may not appeal to everyone, casein could be used for other purposes. Consider serial, for example, which is often coated with sugar to keep flakes crunchy. Could casein coating not accomplish the same thing, while offering a healthier substitute?
Study Co-leader, Laetitia Bonaillie, Ph.D. commented “The coatings applications for this product are endless. We are currently testing applications such as single-serve, edible food wrappers. For instance, individually wrapped cheese sticks use a large proportion of plastic – we would like to fix that.”
Bonnaillie’s group is in the process of working on a prototype of film samples for a small Texas company and has received attention from several other companies. As of now, Bonnaillie says casein packaging should be on store shelves within three years.