Consumers in the United States and Europe were alarmed to hear two stories about mislabeled food last week. In Ireland and the United Kingdom, an Irish government investigation found high levels of horsemeat and pork in ground beef  at the Tesco supermarket chain. Meanwhile, in the United States, This American Life ran an urban legend-esque segment claiming that “imitation calamari” is really made from pig rectum .
So how do regulators and consumer groups figure out what is really being sold at restaurants and markets? The Food and Drug Administration (FDA) in the United States, a host of local regulatory agencies, corporations, and consumer advocates all rely on a small subculture of food forensic scientists: Researchers who use investigative tools to determine that “organic"-labeled fruits are really organic, that your ground beef is really ground beef, and that high-end olive oils isn't being adulterated with cheap soybean oil.
In the United States, the FDA's Center for Food Safety and Applied Nutrition  operates research centers nationwide to ensure the safety of the food supply. Much of this work includes testing products sold in stores to determine they are what they say they are. To give just one example, coffee is commonly adulterated : Due to recent changes in commodity prices, roasters now routinely swap out lower-grade Robusta beans for more expensive Arabica. Although this is legal for blended coffees, regulators and auditors often want to ensure Robusta beans aren't sold in all-Arabica blends. Food manufacturers are also among the groups shelling out cash for product testing; many brands live in fear of lost sales from a food safety or labeling scandal.
For food scientists, this means careful analysis. Both varieties of beans contain different ratios of the two primary compounds in coffee--caffeine and chlorogenic acid--and local varieties have even more particular markers. Figuring out a coffee's origin takes work, but is possible given enough of a cash and time investment. Particular coffee varieties can be traced using, of all things, DNA-based analysis. The type of analysis used to determine a coffee's origin, polymerase chain origin (PCO) analysis, is also commonly used in murder investigations and paternity testing.
One common task in food forensics is determining the origins of fish sold in sushi restaurants and seafood markets. In December, a report from activist organization Oceana claimed that seafood sold in New York is routinely mislabeled . According to Oceana, 39% of the seafood samples they encountered were mislabeled. The statistics are particularly bad for sushi bars: Every single one of the 16 sushi restaurants the organization's investigators visited--no matter what the restaurant's prices or the neighborhood they are in--mislabeled fish and seafood sold to customers. Oceana selected the restaurants primarily on the basis of strong Yelp reviews.
Unfortunately, the fraud at these restaurants wasn't as innocuous as passing processed fish off as scallops or selling tilapia to customers who ordered snapper. 94% of the “white tuna” sold at New York sushi bars really comes from another fish, called escolar. Escolar's name might sound innocuous enough, but, well... Alton Brown, a television chef who knows these things, calls escolar “laxative fish.” Escolar's high level of wax esters leads to intestinal cramping and diarrhea  in many customers. Italy and Japan have both banned the sale of escolar, but seafood industry lobbyists in the United States have defeated attempts to restrict its sale domestically.
Researchers in Italy also used food forensics to track down counterfeit mozzarella distributors. In 2007, Italian researchers conducted DNA testing of mozzarella cheese . Buffalo milk mozzarella cheese is a European Union Protected Designation of Origin (PDO) product that commands a higher price point; a team at the University of Padua found widespread adulteration of retail buffalo milk mozzarella with ordinary cow mozzarella. This study led to a crackdown on cheese fraud--customers were paying higher prices for inferior cheese.
For researchers, regulators, activists, and corporations, the big challenge is the culinary supply chain. So many elements are involved in bringing food from the farm (or ocean, or plantation, or forest...) to table that, even if a company is honest, middlepersons have endless opportunities in warehouses and wholesalers to make a profit by adulterating the product. For customers, that means one thing: being careful about what to eat.
[Image: Flickr user Photosnormandie ]