October 1, 2014 at 8:00 am

Banana Bioplastics are the Food Waste Solution of the Future

In an effort to reduce high levels of pollution in her native city of Istanbul, Turkey sixteen-year-old Elif Bilgin embarked on a project to to reduce petroleum consumption. We’ve all heard about the need to cut down on gasoline and oil but plastics are another important repository for this non-renewable resource. Researching the field of bioplastics, Bilgin discovered that you could create a similarly useful synthetic material using plants.

Potatoes and bananas, with their high starch levels, were particularly well suited to the challenge. Even better the banana peel, which no one eats, had all the right genetic makeup for the challenge but was essentially a waste product. “The peel is something we throw away every day,” Bilgin said in a film about her project, “little do we know, it could be put to much more use.” By turning them into much needed plastics, she wasn’t just cutting down on waste, she was recycling too.

If you’ve ever been handed a biodegradable plastic bag, you’ve encountered bioplastics. Though decreasing our petroleum use is generally a good thing, the technology is not all sunshine and daisies. First, many bioplastics require specific composting or recycling procedures in order to have the chance to actually break apart. Many products are made with a combination of plastic and bioplastic, requiring them to be separated after use. As Kristina Dell wrote for an article in Time, “Is society green enough to use bioplastics? Many of us still don’t recycle all our bottles and cans, and now companies are expecting us to start composting?” Complicating the issue even further is the fact that bioplastics are commonly made from large monocultures like corn. Back in 2008, the market for this new technology was already growing by 20-30% a year. Yet most of what’s used to create bioplastics are food crops. According to The Guardian, 200,000 tons of bioplastics require somewhere between 250,000-250,000 tons of biological material to make it. These facts make research like Bilgin’s even more necessary. The food industry is filled with waste products. The United States alone wastes over 200 million tons of food each year. If put to good use, it could become a lot of plastic.

screen shot elif bilgin banana plastics

Over two years, Bilgin sourced bananas suitable for her experiment. They had to be free of blemishes as well as the same color and size. To turn them into plastic, she dipped them into a preserving sodium metabisulfite solution. Then it was time for chemistry-kitchen magic. The peels were boiled, puréed, mixed with sodium hydroxide (more commonly known as lye) and hydrochloric acid (which you may recognize as the name for corrosive stomach acid). For the last step, she simply baked the mixture; the hardened finished material is something we all know as plastic. Voilà.

The type of plastic she made could easily be used in cosmetic prosthetics and cable insulation. Bilgin’s  project won first place at the Scientific American Science in Action competition and made her a finalist in last year’s Google Science Fair. More importantly, it’s a sign of innovation to come. Because if sixteen-year-olds are able to turn food waste into plastic gold for a science project, imagine what industries with actual funding and full teams of scientists are capable of.

-Tove K. Danovich