Flour, sugar, eggs, butter, plastic? Scientists south of the border have managed to make edible one of the last ingredients bakers might expect to find in a recipe. A team from Southern Illinois University Carbondale was able to turn plastic and agricultural waste into something edible using yeast. The research presented in Chicago this week and led by NASA, was geared toward reducing waste and addressing food scarcity. They were able to program yeast to target waste products and convert them into “edible proteins and flavouring molecules, creating a treat from trash,” biochemistry researchers said in a news release Monday. Calling it an “upcycling method,” they wrote that the technology could be used to sustain life in challenging environments, such as disaster zones or on lengthy missions in space. It’s also a potential solution to the world’s growing pollution problem, researchers said. “Microbes are very clever. So, we are using their traits to solve the problems we created,” said associate professor Lahiru Jayakody. Jayakody said scientists are looking for ways to transform used plastic products. “We thought, why not focus on making food? Because plastic is carbon and food is carbon.” How it works It’s possible to convert the common type of plastic often used to make water bottles into a protein in a lab, using chemicals, researchers said. But the researchers involved in this project opted for another option – something they describe as “simpler and more eco-friendly.” Despite the description of this process as “simpler,” it still differs significantly from the numbered steps you’d see on your average cookie recipe. First, they broke down polyethylene terephthalate (PET) plastic with corn stalks and leaves, and other organic material. More information on this part of the process is included in the news release. They then combined the broken-down PET with programmable yeasts, which were able to reform the pieces of the PET into food ingredients. Those ingredients include proteins, fats, and acids. To turn the product into cookies, researchers added fibre, starch and sweetener, “then extruded it through a 3D printer, forming protein-rich cookies dubbed µBites.” Taste test pending The cookies are edible, according to researchers citing their data, but whether people would actually want to eat them remains to be seen. They say they’re still waiting for “institutional approval to conduct taste tests,” but note that the snacks have a pleasing smell. It’s far from a rave review, but they say that most participants in their research agree “they would be willing to eat the cookies in resource-limited situations.” In the meantime, they’re looking at ways to make the cookies into a product consumers might eat in less desperate times. Use of yeast Baker’s yeast can be used to convert organic material into something like vanilla flavouring, the news release said, while another type of yeast can turn PET into an antioxidant that human bodies convert into vitamin A, meaning future cookies might taste better and be better for you. The hope is for a product that is available “both on Earth and in more extreme environments, like submarines or even colonies on the moon or Mars” within a few years, Jayakody said in the news release. He noted a projected rise in global food demand of up to 56 per cent in the next 25 years, that is currently estimated to put about 30 per cent of people at risk of hunger. “One way to address that, I believe, is by using microbes,” he said. Yeasts and other microbes have long been used as “miniature factories to make a variety of molecules,” researchers said in the news release. They listed insulin as an example; once made from animal pancreases, it can now be made by programmed yeast. Researchers involved in this study have used yeast to “convert molecules present in plastic and agricultural waste molecules into proteins, vitamins and flavourings.”
