Whether you consume it in ice cream, coffee, cupcakes, pudding, or protein shakes, the vanilla（香精） you eat in the future might taste just a little bit sweeter thanks to a surprising new ingredient: used plastic.
Admittedly, it doesn't sound very appetizing. To scientists Joanna Sadler and Stephen Wallace at Scotland's University of Edinburgh, however, what's even less delicious is plastic waste, which currently enters the ocean at a rate of 8 million tons per year—enough plastic waste to outweigh all of the ocean's fish by the year 2050. To help stop the plastic pollution on land and at sea, they've designed a novel way to turn it into vanillin, a chemical substance in vanilla extract that gives it its distinct vanilla smell and flavor.
Although it can be found in natural vanilla bean extract, vanillin also can be made synthetically using chemicals coming from petrol. To create it from plastic, instead, researchers genetically modified a strain of E. coli bacteria so that it can make vanillin from a raw material used in the production of plastic bottles.
According to their research paper, around 85% of the world's vanillin is synthesized from chemicals that are obtained from fossil fuels. That's because demand for vanillin—which is used widely not only in food, but also in beauty products, cleaning products, and herbicides—is far greater than supply. In Madagascar, which grows 80% of the world's natural vanilla, pollinating, harvesting, and curing vanilla beans is a long and painstaking process that couldn't possibly yield enough vanillin for modern appetites. And even if it could, the only way to naturally increase vanillin supply would be to plant more vanilla plantations, which would drive deforestation.
Being able to create vanillin with plastic instead of petroleum means increasing vanillin supply while decreasing plastic waste, reducing industrial reliance on fossil fuels, and preserving forests.
"Using microorganisms to turn waste plastics, which are harmful to the environment, into an important product is a beautiful demonstration of green chemistry," said Ellis Crawford, publishing editor at the United Kingdom's Royal Society of Chemistry.
