Chitosan-based Plastic Wrap May Help Reduce Global Food Waste

In kitchens acroshutterstock_313688300ss America, the same gruesome story plays out. While rooting around in the refrigerator you discover a disgusting, unidentifiable something. It’s so old and rotten that even the plastic wrap swaddling it can no longer contain the odor wafting from it. You wrinkle your nose, shrug your shoulders, discard the spoiled food in the garbage, and go back to hunting down that last bottle of beer you hid from your spouse in the back of the fridge.

What’s one more wasted whatever that was in the scheme of things, right?

At the risk of making you feel really guilty, that’s the kind of attitude that contributes to the 62.5 million tons of food Americans waste every year. In the U.S., about 40 percent of all the food we produce goes to waste, and 80 percent of that wastage comes from homes and consumer-facing businesses like restaurants, according to the report “A Roadmap to Reduce Food Waste by 20 Percent” from ReFED.

Waste happens

Of course, some of that wastage is because our eyes are bigger than our stomachs, but a whole lot of it occurs because food spoils. Exposure to oxygen, ultra-violet radiation (sunlight) and bacteria can cause food to go bad. Even when you take steps to preserve food — such as using plastic wrap or securing it in Tupperware containers — time is not on your side. You need to get to those leftovers before the bacteria and fungi do!

But a new type of environmentally friendly plastic wrap, made from one of the oldest natural polymers in existence, could tip the hourglass in our favor when it comes to keeping food fresher longer.

Earlier this year, researchers at the National University of Singapore announced that they’ve developed a type of food packing material made from chitosan and grapefruit seed extract. In a word, folks, this is genius!

Chitosan is a natural biodegradable polymer, widely used in medical applications, that’s derived from the shells of crustaceans (such as shrimp and lobster). It’s great for medical uses for a number of reasons; it’s biodegradable and biocompatible, easily forms into a film, is non-toxic and — here’s where the genius comes in — naturally antimicrobial and antifungal.

By treating a film made from chitosan with the grapefruit seed extract, the NUS team was able to make plastic wrap that can slow the growth of the fungus and bacteria that lead to food spoilage. What’s more, the film blocks UV light, which is something the plastic wrap you currently have in your kitchen drawer isn’t designed to do. That means the new wrap will also slow down photochemical degradation and oxidation.

Researchers believe the chitosan-based wrap could double the shelf-life of perishable foods like bread. In experiments they conducted in a lab, researchers found bread packaged in their wrap lasted twice as long as bread packaged in synthetic packaging films.

The NUS team will continue to study ways to improve the technology and to assess how well it will inhibit microbe growth and affect food quality in extended usage. They also hope to commercialize the composite film as a packaging material.

“Extending the shelf-life of food products also means reducing food waste, and as a result, reducing the rate of global food loss,” one of the researchers, PhD student Tan Yi Min, said in the university’s press release announcing the discovery. “This will bring about both environmental and economic benefits.”