As the old saying goes, the road to Hell is paved with good intentions. So too do we find that to be the case with plastic, a revolutionary material that’s shaped industries the world over as well as asserting itself as the standard of food packaging. Of course, this all comes at the cost of our overburdened landfills, oceans, and the overall health of our environment. Desperate to find an answer to our plastics problem, some researchers are turning to some pretty interesting alternatives. For the U.S. Department of Agriculture, it seems milk-based packaging might be a viable answer.
Plastic has been championed as the food safety solution when it comes to packaging. Juyost because something is made from plastic, however, doesn’t always mean it makes an effective barrier material. In fact, the thinner films such as those stretched across cuts of meat at your local butcher aren’t all that great at sealing food in and keeping air and moisture out compared to stronger, thicker plastics (thank oxygen permeability for that). Not to mention these films can’t even be recycled, let alone break down naturally in the environment.
Peggy Tomasula and the rest of her team at the USDA have been looking for a solution to this problem. Given their jurisdiction over the farms and fields of America, it only makes sense that their answer comes from the land. In this case, it comes in the form of casein, a milk protein most of us know as a major component in cheese.
What we didn’t know is that casein is looking to be a pretty good packaging material.
A Protein With Potential
According to Tomasula’s team, milk-based films made from casein are “up to 500 times better than plastics at keeping oxygen away from food.” Of course, since casein’s a natural substance we already use (and eat) in food, it’s biodegradable, edible, and sustainable. In case you think your eyes are deceiving you reading that last sentence, perhaps the American Chemical Society can help illustrate what we mean:
They don’t just stop at bioplastic films. Milk-based packaging can also replace single-serve food wrappers like instant coffee or soup pouches. Instead of leaving behind an empty paper or plastic wrapper, casein wrappers will harmlessly melt away into the boiling water, releasing the mixes in question without any waste. And while not technically packaging, casein can also be used to seal cereals and other flake products. Traditionally, your favorite cereal has some sort of sugar coating that lets the flakes keep their crunch in milk; casein does the same thing without rotting your teeth.
Early attempts at harnessing the power of casein were met with skepticism: when using pure casein, it was “relatively hard to handle and would dissolve in water too quickly.” It wasn’t until the team added citrus pectin — a complex carbohydrate found in citrus fruits, namely their rinds and pulp — that milk-based packaging became viable, “[making] the packaging even stronger, and more resistant to humidity and high temperatures.”
Others have been working at the plastic packaging problem too. Microfibrillated cellulose, for example, looks promising by making paper products more durable as well as air- and water-resistant. Agar (that is, a mixture of algae powder and water) has also been making waves as a futuristic, eco-friendly, and edible food packaging material. Both substances, however, are still a ways off from competing against plastic: MFC’s permeability still isn’t up to food safety standards and agar, while edible, has a habit of leaching into whatever it’s containing. Not to mention it shrivels up as soon as it dries out. Admittedly, that’s a pretty neat feature in self-disposing water bottles, but that doesn’t make for the best barrier material for most other foods.
Certainly milk-based packaging is leading the way if it already performs 500 times better than plastic when it comes to oxygen permeability. That isn’t to say, however, that it isn’t without its hurdles.
A Properly Aged Answer
While the outlook on this technology is looking pretty positive, there’s still a few concerns left unanswered. Two big ones come to mind.
First, how will this technology affect the dairy industry? Much like corn fields being converted away from food production in favor of ethanol, how many cows will be needed to produce the milk for this new product? What about all the land for those cows to graze or the methane they produce? After all, methane from digesting cows is becoming a potentially greater concern than the greenhouse gas emissions from our cars. While casein films are effective, are we truly finding a sustainable alternative to plastic or just repeating the cycle with new parts that contribute to the global warming crisis?
On an individual level, the second concern comes from the milk itself. How will milk-based packaging affect those with milk allergies? Mind you, not lactose intolerance, but full-blown histamine reactions and potentially fatal anaphylaxis. Especially if single-serve foods wrapped in casein are used, will people with milk allergies be able to enjoy this packaging revolution or, if this becomes a standard, will they have to use the ol’ paper-wrapped packets instead? Regardless of allergy, these pouches still have to remain sanitary if they’ll end up being dissolved into food. Currently, the USDA suggests packing these pouches in a single larger conventional plastic bag to prevent moisture and dirt from coming into contact with the milk-based packaging.
With that in mind, there are still applications where plastic has no substitute. Casein films, however, could take out a huge chunk of what plastic is already used in food production. At this point, with millions upon millions of tons of plastic wasted each year, anything to eat away at the numbers sustainably is a welcome addition.
Still, this edible solution is the closest attempt we’ve seen so far at potentially replacing plastics in food packaging. It might not be the perfect solution, but if it’s anything that farmers or the USDA (or really anyone in the agriculture business) know, it’s patience, observation, and cultivating quality products. While they’re working on their casein counter-friction to the plastic machine, I’m still wondering one last thing: are they still going to wrap American cheese slices in plastic, or just more cheese?
What a time to be alive.