Plastic bottles can be turned into edible, vanilla-flavour cookies

Plastic bottles and agricultural waste can be converted into consumable cookies via genetically engineered yeast. The team members behind the initiative are currently awaiting institutional approval so they can taste the product. Plastic pollution and food scarcity are two of society’s thorniest problems. Sandhya Jayasekara and her colleagues from Southern Illinois University Carbondale hope to use the former to solve the latter – potentially eliminating both in the process. The first stage of the process is to take used plastic bottles – sourced from a supermarket – and discarded sweetcorn plant stalks and leaves, and put them through a process called oxidative hydrothermal dissolution. This uses heat to break down the materials into components that microbes can digest. Advertisement Those components are then fed to yeast that has been genetically altered using CRISPR gene-editing technology. This allows the yeast to convert the components into a variety of useful ingredients, including proteins, fats and acids, as well as vanilla flavouring and beta-carotene, which the body can convert into vitamin A. Finally, fibre, starch and sweetener are added to the mix, and the paste is extruded through a 3D printer into any desired shape. The resulting cookies have been dubbed µBites, pronounced microbites. The researchers, who are presenting the work at the fall meeting of the American Chemical Society (ACS) in Chicago on Friday, are eager to try µBites for themselves as soon as their university approves the experiment. But they are confident that the cookies are both safe and tasty. “I think it has a pleasant, appealing aroma,” says Jayasekara. “And it will taste good, too. We’ve not tasted it, but it smells good – that’s for sure – like a real cookie.” Team member Lahiru Jayakody, also at Southern Illinois University Carbondale, says it will take 20 years of additional research before plastic waste can be pulled from oceans or landfills and converted to safe and appetising food, but that he hopes the process alone can inspire others to tackle the problem of plastic waste in innovative ways, leading to “a social shift” in the way we think about the problem. But not everyone is convinced that µBites can make a meaningful impact on plastic pollution. Jason Hallett at Imperial College London says the research is fun and interesting, but also, in all likelihood, a practical dead end. “We produce 400 million tons a year of plastic waste. You’re not going to turn it all into cookies,” says Hallet. “So it’s not a solution to the plastic-waste crisis. There’s no way you could do this commercially. We’re not gonna be eating plastic cookies.” The concept certainly faces challenges. In a time when there is growing concern about the amount of microplastics in our environment, food and even our brains, it could be difficult to sell the idea of food that is actually made from plastic. Add the stigma of genetic engineering to the mix, and manufacturers may find a limited appetite for µBites. Hallett says the best solution to the plastic crisis is recycling through processes we already understand, but logistical problems with gathering such widely cast waste and the low cost of virgin plastic mean it isn’t being done on a large enough scale.