Food fraudsters beware: science has found ways to test whether food really is what it says on the tin. Just as crime-scene investigators scour for evidence to reveal a criminal’s identity, researchers have discovered a technique of “fingerprinting” food to see what compounds it contains, and have come up with methods of DNA testing a product to unveil its identity.

With bird flu outbreaks putting food safety in the headlines, researchers from the government watchdog the Food Standards Agency (FSA) have just announced a new battery of food authenticity tests that can reveal secrets about your food, and confirm whether it really is organic or British, or even if the meat you buy is, in fact, dead rat.

Claiming that a food is special is big business. An organic, British-reared chicken, for example, can cost three times more than its bog-standard cousin. And, when there’s money to be made, unscrupulous retailers may be tempted to cheat consumers. Last December the celebrity London restaurant Julie’s was found guilty of serving its trendy clientele ordinary chicken and pretending it was organic. This saved the restaurant £4,200 in a month, but it was fined more than £11,500.

Since 2000, scientists from the FSA have beendevising tests to catch scammers out. Seven years of research has paid off and its ar-moury of new food tests is soon to be unleashed by local trading standards officers with spot checks on shops, markets restaurants and supermarkets. “Enforcement labs will be able to examine areas which, until now, they had not been able to do in a very effective way,” says Dr Mark Woolfe, an FSA scientist.

Trading standards officials, working on behalf of the FSA, can raid any part of the food chain, from the farm to the factory and supermarket, to make sure that nothing fishy is going on. They take samples and send these back to the lab. Tests then reveal the food’s identity and confirm whether a full-scale investigation is needed. At this stage, the tests cannot be undertaken on site, but the scientists are working on more compact, movable testing devices.

“I don’t think we’ll ever get to the stage when a test is as quick and portable as, say, a pregnancy test,” says Dr Woolfe. But the very existence of a test has some manufacturers shaking in their boots. “These tests will certainly protect the consumer. We’ve found that when food manufacturers know the tests are available then they are a bit more careful.”

It is a tough industry. Food is getting cheaper, but food production laws are getting tighter, so manufacturers are finding themselves in the increasingly difficult position of trying to keep prices down while maintaining high standards. “There is conflicting pressure here,” says Dr Woolfe. And some see fraud as a way out.

Here is a rundown of the tests soon to be unleashed, to make sure that you know exactly what you’re eating . . .

ORGANIC

Meat
These tests detect the type of drugs that livestock have been given. Meat can be called organic only if it is treated no more than once a year with antibiotics, and only if the animal has got an infection, not as a growth promoter. Antibiotic drugs are laid down in the bone, like rings on a tree. Slice the bone under fluorescent light and these rings glow. This allows the scientists to count the number of times an animal has been treated with antibiotics.
Fruit and veg This test looks at whether a fruit or vegetable crop has been treated with synthetic fertilisers. Man-made fertilisers contain a slightly different form of nitrogen from organic fertilisers, and this can be detected. According to Dr Woolfe, the test is very good at picking organic tomatoes and mushrooms from nonorganic, but struggles slightly with lettuce and carrots because of the way they take up the nitrogen through their roots.

CHEMICAL FINGERPRINTING

This test can reveal the truth or otherwise of a “British” label, revealing where in the world a food comes from. To find out the source of beef and poultry, scientists look at the amount of carbon, hydrogen, oxygen, nitrogen and strontium (an element found in rocks) in the meat.

Each part of the world has a particular ratio of these elements in the soil and air. When animals eat grass and drink water, this chemical fingerprint is incorporated into their protein and fat, which can be analysed and the region they originate from broadly identified.

“Even if we can’t say exactly where it comes from, we can say where it doesn’t come from,” says Dr Woolfe. The same technique can be used to find out if people are trying to flog tap water as mineral water.

As part of a European food-testing project called Trace, scientists have developed a test to differentiate mineral water from ordinary mains water. Mineral water from different areas contains a different chemical fingerprint, dictated by the type of rocks and soil that the water runs through. For example, water meant to be from a region of France would contain a particular chemical fingerprint. If it doesn’t, it’s likely to be tap water. Scientists are putting together a global database of chemical fingerprints using geological maps.

The technique can also be used to test whether fish has been farmed, or was caught wild and had roamed free all its life. By law this now has to be stated on the label and wild fish can cost up to five times as much as farmed.

Different chemicals are incorporated into the fish oils from different food. As wild fish have a very different diet from farmed fish, their oils will contain different compounds

DNA TESTING

This technique can prevent people from passing off one type of meat or fish as another. “Certain fish such as cod are now much more difficult to obtain,” Dr Woolfe says, “but people still want it when they go out to eat.” An investigation by the FSA a couple of years ago found that about 7 per cent of restaurants and fish and chip shops were not selling the fish they claimed to. Different fish species have different DNA, so by using a relatively simple DNA testing technique, scientists can identify the species.

They can use the same principle for meat. They know the DNA of all the conventional meats: beef, pork, chicken, lamb, turkey; and also the more exotic: donkey, primates, antelopes, bush pigs and large rodents.

These exotic meats may be imported illegally and, although some are allowed in, they must be killed at licensed premises and not caught in the wild and smuggled into the country in luggage, which is often the case.

The great basmati rice rip-off

The name “basmati” is as strictly controlled as champagne, with only nine varieties, grown in specific areas of India and Pakistan, qualifying for the title. But, when 360 bags labelled “basmati” from shops across the UK were genetically tested by the Food Standards Agency in 2003, it found that nearly half contained as much as 60 per cent cheaper grains. Two Essex companies were prosecuted as a result. Meanwhile, since then the Rice Association has found that the number of adulterated samples on sale in UK shops has fallen from 46 per cent in the 2003 survey to 16 per cent today.

JILL TUNSTALL

Crunchy numbers

£2 million is the amount Coca-Cola spent on the launch of its bottled water Dasani in 2004, only to withdraw it after it was revealed to be purified tap water.

1.5 million items of counterfeit food and drink were seized in the EU in 2003.

267 per cent is how much more you pay for organic chicken compared with ordinary birds

SOURCE: TIMES DATABASE

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