Lesley Chesson once took a road trip and collected as many "milk chugs" from McDonald’s Happy Meals as she could stuff inside a giant cooler in the back of her car. Another time, she requested students bring her cans of Coca-Cola. Chesson also asked dairy farmers to fill travel-sized shampoo bottles and overnight her milk samples. It’s not that she’s a hard-drinking researcher. These samples were all destined for forensic analysis.
Chesson is what you might call a food sleuth, a scientist whose primary interest is food authenticity. She’s a staff scientist and researcher at the University of Utah and also works at a research company called IsoForensics in Salt Lake City. What her work reveals: Even when a label can’t tell you where a food is coming from, chemical fingerprinting can.
Food fraud, economic adulteration, and food counterfeiting tend to fly under the radar of federal regulators, despite estimated global losses of about $49 billion, because adulteration doesn’t always translate into sick and dying kids (perhaps with the notable exception of melamine in milk). Moreover, says John Spink, a expert on food fraud at Michigan State University: “In many cases, there is not a clear violation of a law or regulation. This is a chess-match with a very intelligent, resilient, creative, and driven adversary.”
If a fake looks and tastes the same (and doesn’t necessarily do the consumer any physical harm), fraudsters can make more money selling corn-fattened cattle, then call the burgers “grass-fed.” They can jack up the price on “organic” eggs or make a killing off beet sugar if they call it “honey.” Chesson says, “If you’re going to pay a premium, there is an incentive to cheat and mislabel. How do we anticipate that and stop that before it starts?” Good question. One with a straightforward answer: an optical stable isotope analyzer. Basically, think of it as a label lie detector; a breathalyzer for dinner.
These spectrometers measure stable isotopes in a gas, which first requires researchers to combust their samples. Since a Big Mac and a Coke are obviously not a gas, you have to convert them into constituent parts--at 1,000 degrees Celsius--and then bounce light off the gas. Based on the rate at which the light is absorbed and diffused in the gas, researchers can determine what isotopes are present in a given sample. Isotopes are forms of elements like carbon, nitrogen, or oxygen; these elements are found in beef, milk, honey, and just about anything you put in your mouth.
Because these subtle, detectable variations coincide with climate, growing conditions, and manufacturing processes, a Big Mac’s carbon and nitrogen ratios can give researchers an indication of whether an animal was raised on grass or grain (and yes, scientists have shown that there are regional variations in the hamburger that’s better known as an icon of homogeneity and globalization). Similarly, predictable variations in hydrogen and oxygen masses have been mapped across the United States and can tell you, with a certain confidence, where bottled water was pumped out of the ground or where the water in Budweiser originated.
For decades, this kind of forensic analyses required a million-dollar piece of instrumentation the size of a room. Now, smaller shoe-box spectrometers, produced by companies like Picarro and Los Gatos, both in California, could fit in a backpack or a hatchback. This could put the technology in more people’s hands, but the biggest hindrance to its widespread application remains American ambivalence. In the European Union, laws protecting the geographic origins of Parmesan cheese and Champagne are far more widespread. You could say where there’s a will, there’s also way more widespread application.
“You really have to get a market that cares about where food is coming from before there’s money behind some of this research,” Chesson says. “There are definitely people who are starting to pay attention to where their food comes from, who want to make sure that it’s produced in a certain way or coming from a certain area.” Last year, for example, she helped high school students investigate beef. What they found: Food sleuthing really can reveal the truth in labeling. Next up? They’re examining the enduring mystery of the school cafeteria’s mystery meat.