Scientists Combat Pollution by Turning Recycled Plastic Into Vanilla Flavoring

A new process by which recycled plastic is transformed into vanilla flavoring means that sweet treats of the future might be sustainable as well as delicious.

According to EcoWatch, a study published in Green Chemistry last week explained how University of Edinburgh scientists harnessed the power of the common E. coli bacteria to turn used plastics into something functional—specifically, the flavor compound vanillin.

The university's announcement said vanillin "is the primary component of extracted vanilla beans and is responsible for the characteristic taste and smell of vanilla." And it's in incredibly high demand: aside from uses in food and cosmetics, vanillin finds its way into "herbicides, antifoaming agents and cleaning products."

While vanillin was originally derived from vanilla extract, it's now commonly "synthesized from fossil fuel chemicals," EcoWatch said.

"This is the first example of using a biological system to upcycle plastic waste into a valuable industrial chemical and this has very exciting implications for the circular economy," Joanna Sadler, the study's first author, said in the university's statement. "The results from our research have major implications for the field of plastic sustainability and demonstrate the power of synthetic biology to address real-world challenges."

The new technique specifically offers a second life for polyethylene terephthalate (PET) plastics—the lightweight, durable plastic used for items like disposable water bottles and food packaging. The method takes a molecule contained in PET plastics, terephthalic acid (TA), and uses E.coli bacteria to turn it into vanillin via several chemical reactions.

While fossil-fuel derived PET plastics are recyclable, only a small amount is recycled. EcoWatch said that, in the U.S., "only 8.7 percent of the total plastics produced is actually recycled." Additionally, "plastics lose around 95 percent of their value after they are used only once." Turning PET waste into vanillin—the market for which is poised to hit approximately $724 million by 2025—would bring us one step closer to the "circular" economy described by Sadler.

The scientists involved in the study believe that the plastic-derived vanillin will be safe for people to eat, but further research is required. The team hopes that the discovery lays a foundation for the future "upcycling" of waste via synthetic biology.

"Fundamentally, this work substantiates the philosophy that post-consumer plastic may be viewed not as a waste product, but rather as a carbon resource and feedstock to produce high value and industrially relevant materials and small molecules," the study concludes.