Scientists have transformed PET plastic into nutritious edible cookies, an innovation that could help address both pollution and hunger in one fell swoop. That is, if people can accept the idea of eating it.
Dubbed “µBites” (pronounced “microbites”), the cookies are made using yeasts that have been programmed to turn plastic into edible protein. Sandhya Jayasekara, a Southern Illinois University Carbondale graduate research assistant, presented the project during the American Chemical Society’s Fall 2026 meeting on Monday.
Commonly used to make disposable water bottles, PET plastic has low impurities, and is composed of approximately 60 percent carbon, 30 percent oxygen, and four percent hydrogen. Meanwhile, protein is formed from amino acids, which consist of a central carbon atom bonded to four other groups.
“We were trying to develop technologies for plastic upcycling to make more valuable products,” associate professor Lahiru Jayakody said in a statement. “We thought, why not focus on making food? Because plastic is carbon and food is carbon.”
To transform PET plastic into food, researchers went through a 32-step process which included using microorganisms to convert molecules into proteins, vitamins, and even flavourings. Microbes such as fungi and bacteria are already commonly used in the food industry, such as in fermentation, as well as to make molecules like insulin. Specific strains of bacteria have also been found to be capable of breaking down PET plastic. However, breaking down plastic then reforming it into something edible is newer territory.
“Global food demand is expected to rise 35 to 56 percent by the year 2050, and about 30 percent of the world population will be at risk of hunger in the future,” said Jayakody. “The way to address that, I believe, is by using microbes.”
Mashable Light Speed
How do you make a cookie out of plastic?
Starting with PET plastic and agricultural waste such as corn stalks, the scientists first put the material through an environmentally friendly process called oxidative hydrothermal dissolution. Also developed at Southern Illinois University, this subjects biomass to small amounts of oxygen in water at high pressure and temperature. Doing so breaks down the solid biomass into water-soluble fragments that are a low molecular weight, making them easier for microorganisms to handle.
Once complete, the resulting carbon-rich liquid was fed to several strains of pre-programmed yeasts, which used metabolic processes to turn them into food components such as proteins, fats, and acids. The researchers also developed yeasts that create components which improve the µBites’ nutritional value and taste, or even alter its colour. This includes one that uses plant biomass to make vanillin molecules, imparting the cookies with a vanilla smell and flavour, and another that produces beta-carotene to give them a golden colour as well as vitamin A.
The researchers then added fibre, starch, and sweeteners to the thick biomass, put the whole mix in a 3D printer, and printed themselves out some protein-rich µBites cookies. Pop them in a microwave to cook, and bon appétit.
Can you try a plastic cookie yet?
Well, bon appétit in theory. Exactly what the µBites taste like is still unknown. The researchers have yet to sample the cookies themselves, showing remarkable self-restraint as they wait for approval to conduct taste tests (meaning the official go-ahead to test on humans). However, the µBites have reportedly “received high marks on aroma,” with most of the team indicating they’d be willing to try out this particular culinary experience in situations where food is scarce.
Further development is underway to make the cookies into a “more attractive, consumer-friendly product” according to Jayasekara, with the intention that they eventually become more than a last resort food option. Even so, it will likely be a while before you see µBites on supermarket shelves. Jayakody hopes the cookies might be ready for public consumption within a few years, and could assist with feeding astronauts, submariners, and others in extreme circumstances.
If µBites are cleared for public consumption, there’s also the psychological barrier that potential diners will have to overcome. Though research indicates that the cookies are safe to eat, convincing people of this will likely be difficult considering the well-known dangers of ingesting plastic. The µBites may not be plastic anymore, but their origins will certainly spark some apprehension.
The Southern Illinois University Carbondale team originally developed the µBites technology for the NASA Deep Space Food Challenge. Running from 2021-24, this competition incentivised novel innovations that could help address food needs during space travel as well as in harsh environments on Earth. µBites won a small grant as a Phase 1 winner, before receiving further funding from the U.S. National Science Foundation‘s Faculty Early Career Development Program (CAREER).
