Your Future Cookies Could Be Made from Upcycled Plastic Bottles

Scientists working on a NASA-funded project have programmed yeast to convert plastic and plant waste into edible, protein-rich snacks like cookies, which could sustain life on deep-space missions and in disaster zones.

You might be wary of microplastics in your food, but a team of researchers in the US have deliberately used plastic to make new food that could have significant implications for food security and space exploration.

In a project funded by Nasa, scientists from Southern Illinois University (SIU) Carbondale have used microbial fermentation to turn the waste from plastic bottles, plants and other biomass into edible cookies.

The tech upcycled polyethylene terephthalate (PET), a material used to make soda and water bottles, with specially designed yeasts to turn one major problem (plastic pollution) into a means to solving another (food insecurity).

“We were trying to develop technologies for plastic upcycling to make more valuable products. We thought: ‘Why not focus on making food?’ Because plastic is carbon and food is carbon,” Lahiru Jayakody, an associate professor at SIU Carbondale.

How scientists turned plastic into cookies

The researchers noted that microbes have long been used as miniature factories to produce a variety of molecules, such as insulin (which used to be extracted from animal pancreases). That’s the same principle they’re using to programme a variety of yeasts, including baker’s yeast, to convert the molecules present in plastic and agricultural waste into proteins, vitamins, and flavourings.

PET plastic contains molecules with lots of carbon that could be rebuilt into something like a protein, and while that could be done using chemical reactions and solvents in a lab, a simpler, more eco-friendly solution is to let microbes do the work. “Microbes are very clever. So, we are using their traits to solve the problems we created,” said Jayakody.

The team put PET, discarded corn plant stalks and leaves, and other biomass through a proprietary process called oxidative hydrothermal dissolution, which was created by SIU Carbondale geology professor Ken Anderson.

This method uses water and oxygen at high temperature and pressure to break down tough material into microbe-accessible pieces. Then, these pieces are fed to the programmed yeasts, which reform them into a variety of new food ingredients, including proteins, fats, and acids.

Finally, the scientists added fibre, starch and sweeteners to the mix and then extruded it through a 3D printer, forming protein-rich cookies dubbed µBites (pronounced “microbites”).

While data shows that the plastic-derived µBites are safe to eat, the team is awaiting institutional approval to conduct taste tests. For now, the cookies have received high marks on aroma, with most participants saying they’d be willing to eat them in resource-limited situations.

In the future, the scientists aim to also produce the main ingredients in µBites using microbes, including the starch, fibre and sweetener, with the hope that the product would be ready for public consumption within a few years.

Plastic-derived food could sustain life in extreme environments

The research was funded by the Nasa Deep Space Food Challenge, which is focused on creating food for astronauts in the resource-limited environment of deep space.

The cookies currently cost $60 per kg to produce, but the SIU Carbondale team said improving the yeast’s efficiency and scaling up production will reduce this price in the future.

The researchers also explored how µBites could be a product consumers can choose in everyday circumstances. Graduate student Sandhya Jayasekara, who worked with Jayakody on the project, created yeasts that can produce more food additives.

This means baker’s yeast can now produce vanilla flavouring from plant biomass and a different strain can turn ethylene glycol from PET into beta-carotene, which the body can convert into vitamin A. “We’re using microbes to develop the cookie into a more attractive, consumer-friendly product,” Jayasekara said.

The tech could emerge as a key solution for plastic pollution. Derived from petroleum, plastic takes 20 to 500 years to break down and is responsible for 3.4% of global emissions – and that share will only increase as production triples by 2060. These materials are hard to recycle and end up in landfills, where they can leak microplastics into our soil and water supply.

The SIU Carbondale scientists suggest the plastic-derived cookies could sustain life in extreme environments on Earth, like disaster zones and submarines, as well as on deep space missions and colonies on the Moon or Mars.

“Global food demand is expected to rise 35-56% by the year 2050, and about 30% 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.”

The research comes shortly after experts working with the World Economic Forum called for a shift in how food is produced for space missions, partly through the incorporation of technologies like cellular agriculture, alternative proteins, and 3D-printed foods into the space food system.