What's on your plate? Food fraud is common, but there are easy solutions
Food substitution is especially rife in the fish industry. Once fish is filleted and skinned, species can be difficult to distinguish. (Fotolia.com / April 24, 2013)
These problems are not new. Food fraud is rife in the fishing industry, and rice, olive oil and other products have been plagued by substitution issues. Yet there are easy solutions. DNA databases and the falling cost of sequencing can close the holes in our food chain. And this may be a prime time to reconsider our prejudices about what's palatable and what's not.
After tests in Ireland found horsemeat in "beef" burgers sold in several supermarket chains, the UK's Food Standards Agency (FSA) demanded that all food businesses test their beef products by February 15, to give an idea of how widespread the problem had become.
"I highly suspect there will be more horsemeat discovered," Liz Moran, president of the Association of Public Analysts, said at the time. APC scientists would be doing much of the analysis.
For now, the FSA is only looking for horsemeat, but other animals may be out there, says Moran. Donkeys and rabbits are more likely than rodents and pets, she says.
"Many local authorities don't do meat testing from year to year. By law, companies have an obligation of due diligence that their food is what they say it is, but some companies will do as little as they can get away with."
It's not yet clear where the horsemeat came from or why Ireland's Food Safety Authority decided to test for horsemeat, since this is not routine.
"It may have been a tip-off," says Moran.
Tests do take place in the United Kingdom, but only when local authorities ask, or companies undertake the process themselves. Such tests look for proteins specific to beef, pork, poultry and lamb. They are relatively cheap per sample, but do not identify other animal sources. That is done by DNA analysis, which costs more.
"The vast majority of companies will rely on their suppliers' paperwork and their suppliers will rely on their suppliers' paperwork," says Moran. "This can pass through eight or nine organizations. Anyone can produce good paperwork, but unless you test every batch, slip-ups happen."
Difficulties in pinning down the exact source of the horsemeat make it difficult to say how safe it is to eat. The FSA says there are no known safety issues at present, but have ordered tests for the anti-inflammatory drug phenylbutazone, or "bute."
"We consume foods with low levels of drug residues all the time," says Christopher Elliott, director of the Institute for Global Food Security at Queen's University Belfast, UK. Bute is an exception. It is banned in food for human consumption in Europe and the U.S. because of a rare but nasty side effect that can cause a bone marrow disorder called aplastic anemia.
"This drug cannot be used in food-producing animals, as there is a risk, albeit very small, of severe adverse reactions," says Elliot.
As New Scientist went to press, the FSA had not ordered tests for any other drug, but with allegations flying that the horsemeat may have come from retired racehorses, tests for drugs like steroids -- used illegally to boost growth -- could be coming. Still, Moran thinks the health risks associated with this are likely to be low.
"If drugs such as steroids were present in a high level in a wide range of products that people had been feeding to their kids for 10 years, then I would be concerned," she says. "But that's fairly unlikely."
Other industries may offer solutions for the meat sector.
"Food substitution is rife in the fish industry," says Paul Bentzen at Dalhousie University, in Nova Scotia, Canada. Once fish is filleted and skinned, species can be difficult to distinguish.
Last December, Oceana, a conservation organization based in Washington, D.C., published a report detailing seafood substitution in New York City. Of 142 samples from 81 retail outlets, it found 39 percent were not what they claimed to be. Similar results came from Boston, Los Angeles and Miami.
The U.S. Food and Drug Administration is taking action. It has published a DNA database for about 250 commonly eaten species of fish, which can be used to authenticate a sample at any point in the food chain. Other projects are in the pipeline. The "barcode of life" being developed at the University of Guelph in Ontario, Canada, for example, has collected sequences for over 8,000 fish species.
While fish substitution may not evoke as much of the "yuck" factor as horsemeat of dubious origin, it can have serious consequences. Efforts to conserve fish stocks rely on a fully traceable food chain. And Oceana's study revealed that 94 percent of "white tuna" was not tuna at all, but escolar (Lepidocybium flavobrunneum). Consumption of more than 100 grams or so of this species causes severe diarrhea.
DNA databases could be developed for meat, too, says Bentzen. He says it costs just a few dollars to sequence a fish sample's "genomic barcode" to identify its species.
"I can't see any excuse," he says. "For a widely distributed product there should be enough routine sampling that this flagrant and widespread substitution should simply not occur."
Genetic testing can even make it possible to trace not only the country and farm a piece of beef comes from, but also the individual animal. Given samples from every animal in a herd, Israeli company Autentica can create genetic barcodes for each one using a relatively cheap analysis of 25 single nucleotide polymorphisms -- small variations in the genome sequence that are unique to each animal. The barcodes can then be used to track animals through the food chain.
While the FSA has made a commitment to work with the food industry to identify the best points in the supply chain to test authenticity of meat products, it remains to be seen whether companies will be willing to accept new regulation.
"In the short term, the FSA is likely to demand that meat suppliers do more DNA testing, but companies will be against that in the long term because it will push up the price of their product," says Moran. "For low-grade foods, this just won't happen."
The technology to help solve the problem is available and getting cheaper. Whether it is used is in the hands of industry and consumers.