Basmati is not the only superior-quality food that has been targeted by fraudsters. Honey, whisky, gin, vodka, fruit juice, butter, cheese, meat, fish, coffee and even potatoes: they have all been packed out with inferior brands and found their way into supermarkets, shops and bars.
Food fraud is big business. For obvious reasons no one knows its true extent, but spot checks and surveys suggest that criminals and crooked food producers cheat shoppers out of hundreds of millions of pounds every year. "When we have done surveys on individual foods the level of fraud is often around 10 per cent," says Mark Woolfe, a scientist in the FSA's enforcement division in London. "The UK food sector alone is worth around £70 billion per year, so a small percentage of fraud can be worth a lot of money."
But fraudsters had better watch their backs. From sophisticated chemical analysis and satellite imaging to DNA tagging, scientists are devising new techniques to track food from farm to fork. The European Union is so concerned about the problem that earlier this year it launched a continent-wide project to boost the development of these technologies. The food detectives are fighting back.
The first written account of food fraud dates back to 1820, when Fredrick Accum, a German chemist, published A Treatise on Adulterations of Food, and Culinary Poisons, which exposed culinary sharp practice in London. It detailed how bakers cut their flour with alum and chalk to make loaves whiter, and tipped in plaster and sawdust to make them heavier. Brewers added substances like the poison strychnine to beer to make it taste bitter and save money on hops. Perhaps worst of all was the use of lead, copper or mercury salts to make brightly coloured sweets and jellies that would be attractive to children.
Today tight controls on food safety have largely stamped out adulteration that might lead to health problems. So unscrupulous food producers are finding ways of debasing food without raising the safety alarms. The big money now lies in diluting expensive brands with cheaper, low-quality lookalikes. The higher prices that people will pay for "premium" foods from a particular place, such as Parma ham, Greek olive oil and Scotch whisky, coupled with the increase in global trade, has meant faking origin has become particularly lucrative. The unprecedented boom in demand for organic food has given fraudsters another high-price market to exploit, especially as there is no definitive way of confirming whether a product is genuinely organic (see "Forensic organics").
After discovering the basmati rice scandal, the FSA began developing a new DNA-fingerprinting technique - like that used by the police to trace crime-scene DNA to its owner - which could be used by food-standards inspectors across the UK. "We had been looking for ways of authenticating basmati for many years and then we had this breakthrough with the DNA test," says Woolfe. As a result, the FSA has begun prosecuting fraudsters: earlier this year, a court fined two Essex-based companies, Basmati Rice and Surya Rice, over £8000 each for selling packs labelled "basmati" that were adulterated with between 55 and 75 per cent non-basmati rice. The agency claims this new surveillance has cut basmati fraud dramatically. It might be right. Earlier this year the Rice Association, a British trade body, conducted a survey that found just 16 per cent of tested samples were diluted with high levels of non-basmati rice.
The FSA and its EU partners now use the technique to check whether products are free of genetically modified organisms. In September, Dutch authorities identified GM material in long-grain rice from the US labelled GM-free. This sparked a flurry of testing across Europe on American long-grain rice.
Takeshi Nishio, from Tohoku University, Japan, has invented a way of pre-empting rice bootleggers by using a genetic equivalent of a certificate of origin. He has selectively bred a variety of Koshihikari rice - a high-quality strain that connoisseurs consider to have a superlative flavour - to have a specific genetic marker. The Uonuma district of Japan is known for producing high-quality crops of this rice, so farmers are concerned that their reputation should not be tarnished by inferior rice falsely sold under the district's name. Nishio hopes to sell his genetically distinctive rice under licence to Uonuma farmers and plans to apply the same idea to other cereals and vegetables in the future.
Without a scheme like Nishio's, DNA fingerprinting isn't enough to identify food from a particular location, rather than just being of a particular species. Many foods can be grown anywhere that has the right climate, so something more is needed to identify the geographical source of the crop. Robert Oger, from the Walloon Agricultural Research Centre in Belgium, wants to solve the problem by keeping an eye on crops as they grow. As part of GeoTraceAgri, a project funded by the European Commission, he has been looking at ways of using aerial and satellite data to verify the origin, quality and quantity of crops.
First Oger and his team visit farms under surveillance to gather statistics about their production capacity: for example, they will note what kind of crops they grow and calculate expected yields based on local soil and climatic conditions. Back in their lab, they monitor the farm via satellite images to see how well the crops develop and identify external impacts, such as how often pollution from a nearby power station drifts over the fields. "If a field is monitored by satellite we can see how many trees a farmer has got and therefore how much they can reasonably produce," Oger says. He hopes the surveillance will deter producers from bolstering their output with inferior product and passing it off as being from a particular farm or region, and help him detect the location of inferior or contaminated crops.
Eventually, he would like to see food products labelled with a geographical identification number that customers could key into a website to see for themselves the olive trees that their olive oil came from, for instance. "The idea is to build something similar to Google Earth for food products, so that someone can see exactly where the bottle of wine on their table came from," he says.
While satellite monitoring can spot pollution and estimate reasonable yields, and DNA marking can identify a species, neither can say for sure whether a food comes from a specific site. That's where chemical analysis comes in. TRACE, an EU research programme, was launched earlier this year to develop a technique that tracks food back to the soil it grew in. Locked inside every plant and animal is a chemical memory of the weather and environment it grew up in. This is found in the ratios of various isotopes - different forms of a single chemical element that have different atomic masses. All food and drink contains hydrogen and oxygen, for instance, that got there when the animal or plant drank the local water, and hydrogen and oxygen have both heavy and light isotopes. The ratio of light to heavy isotopes is a unique signature of a particular climate and geography. For example, in cold climates evaporation is less vigorous and fewer heavy isotopes make it into the rain-cloud mix. Consequently English rain (and English lamb) has a higher proportion of lightweight oxygen and hydrogen isotopes than Spanish rain (and Spanish lamb). This relationship can also be used to distinguish coastal from inland areas and mountains from plains: the concentration of heavy isotopes in raindrops tends to decrease as clouds move inland or gain altitude.
"The technique is most powerful when used to look at products made solely from raw materials sourced from small, distinct geographical regions, as is often the case with protected foods," says Simon Kelly, a scientist at the government-funded Institute of Food Research in Norwich, UK. To narrow the food's origin down even further it may be possible to exploit isotopes in the soil and rocks. "Geology can change over just hundreds of metres, so potentially we can pin down an individual farm or valley," says Kelly.
Isotope analysis can also help in establishing broad groups of plant species in a sample. For example, Woolfe has used natural variations in carbon isotopes between different crops to work out whether juice drinks are indeed "pure" and from a specific place, as packets often claim, or diluted with cheaper juice from elsewhere. The idea relies on a basic observation of plant biology. All plants consume carbon dioxide to produce sugars during photosynthesis. They do this by building sugar compounds containing either three or four carbon atoms. This labels them as "C3" plants (such as apples and other fruit) or "C4" plants (for example, sugar cane). C4 plants absorb the carbon-13 isotope faster than they do carbon-12 and more than C3 plants do, so the ratio of carbon-13 to carbon-12 in C4 plants is, on average, higher than in C3 plants. In one survey, Woolfe found that apple juice, which should contain only C3 compounds, also contained a high level of carbon-13 isotopes, indicating the presence of a lot of C4 plant product - in that case, sugar-cane juice.
Isotopes can even be used to reveal what food your food ate. This has been the focus of work at the Central Science Laboratory (CSL) of the UK's Department for Environment, Food and Rural Affairs in York, where researchers have developed a carbon-isotope technique to test what chickens were reared on. "We can check whether the more expensive 'corn-fed'-labelled chicken really is corn-fed," says Paul Brereton of the CSL, who is also director of the EU's TRACE programme.
Such analysis is also a key component in distinguishing farmed from wild fish. Farmed fish tend to be fatter because they eat more and are less active than their wild cousins, says Woolfe. The difference between farmed and wild fish due to different diet and exercise regimes shows up in the fatty acids and the carbon and nitrogen-isotope ratios in fish oil. "We can differentiate between wild and farmed fish including species like salmon, sea bass and sea bream," he says.
Kelly and his colleagues are now building isotopic maps of Europe so that products such as Champagne, Stilton cheese and Parma ham can be confidently matched with their place of origin. For prized regional products such as these, isotopic maps will be invaluable in verifying a product's origin and preventing it being devalued by cheap copies.
However, seasonal variation in the weather and local geological quirks mean that isotopic analysis can never provide a perfect location fix. "Natural variation means that figures can overlap," says Andrew Mackie, who works at the British government's Analytical and Scientific Services laboratory in Edinburgh. "In some instances isotopic analysis can only provide intelligence, not evidence for a court of law," says Kelly.
But combined with other evidence it can be an invaluable tool. In 2003 German authorities combined isotopic evidence with paper-trail analysis to put a stop to a sophisticated scam, known as "carousel fraud". A group of German companies had been illegally claiming subsidies by trading EU-made butter to and from Estonia (then not a member of the EU). Each time a butter lorry crossed the border from Germany to Poland the companies were given EU export subsidies. Once in Estonia the butter was repackaged and labelled to make it look like it had originated in Estonia, heaved back on a lorry and hauled back to Germany. This time, the importers took advantage of a tax break on foreign imports aimed at increasing trade with prospective EU member countries, as Estonia then was. The investigation revealed that 22 out of 25 butter samples taken from Estonian-labelled butter imported into the EU were not Estonian. In at least one case, the isotopic ratios of hydrogen and oxygen in a butter sample indicated it could only have come from Ireland.
With a battery of new tests at their disposal, scientists are scrutinising many of the foods we buy and finding ways of positively identifying them. The FSA, meanwhile, is about to publish the conclusions of five new surveys of fruit, fish and meat fraud. The next step is to co-ordinate the data and make it easy to follow food from farm to dinner plate. "Eventually we want to integrate these methods into electronic systems that will track food from the field onwards, right until it reaches the kitchen," says Brereton.
Tougher problems are ahead for the food detectives. "The biggest challenge now is food sold under 'ethical' labels, such as Fair Trade and organic, and those concerning animal welfare and countryside protection," Woolfe says. These products are sold at a high price, but there is no technical way of checking any of these claims. That's what it's like in the fight against food fraud, though: no sooner will the scientists find a way of stopping a fraud than the fraudsters will find a new way of covering their tracks. "It is cat and mouse," says Brereton.
Kate Ravilious is a writer based in Edinburgh, UK
From issue 2577 of New Scientist magazine, 11 November 2006, page 40-43
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