How do they find horse meat in hamburger?

The European food industry shudders in the face of the horse meat scandal. Although the headlines have focused on horse meat, pig meat was also found in beef products. As Europeans launch a broad quality control program, the extent of the deception in the food chain has appalled the public, resulting in broad food product recalls and reaching even to Ikea's meatballs and Taco Bell.

All this got us wondering about the testing that spurs these shocking discoveries: a whole new method sheds light on what is really in our food.

Hunting for horse meat

It started when the Food Safety Authority of Ireland (FSAI) found "beef" products that contained horse and pig meat, publishing the results of their study in January 2013. Most of the products had low levels of horse or pig meat. The pork could be attributed to cross-contamination in facilities that process both types of meat, but the horse meat mystery demanded answers, especially as one product, Tesco beef burgers, quantified at 29% horse meat.

The FSAI found that the mis-labeled meat presented no hazard to human health, so it did not kick the reporting into high gear through the European Rapid Alert System for Food and Feed -- resulting in mis-labeled products remaining on the shelves for weeks. But the consumer outrage has made it clear that our food choices are more than simply a health issue.

Horse meat is sold legally and eaten in many European cultures, but is considered akin to eating the family pet by others. Some people abstain from eating pig meat on religious principle, which makes even the inadvertent inclusion of pig in beef products particularly offensive.

A tale of new testing

Behind the scandal, this story reflects the evolution of methods for testing food quality and label claims. The method that uncovered the horse meat contamination, Polymerase Chain Reaction (PCR) analysis, is credited to Alec Jeffreys at the University of Leicester. Now widely used as "DNA fingerprinting" in criminal and paternity investigations, the methods began interesting food safety advocates as a way of detecting genetic modifications in foodstuffs or of tracing food supply from plate back to farm.

According to the Jane Ryder at the press office of the Irish Food Safety Authority, most EU state agencies have not used DNA testing for food quality. But the FSAI has started conducting a DNA-based testing program each year targeted at verifying label/contents claims. In past years, the agency found Norwegian farmed salmon being sold as wild Irish salmon and cheaper coley instead of cod in the famed fish and chips. This year, the agency decided to go snooping for horse and pig in products labeled "beef".

In the wake of this scandal, attempts have been made to question the validity of the test methods used in this case. But the FSAI submitted 20 sub-samples, 10 positives and 10 negatives, to a second lab -- without informing them of the previous test results. The second lab reported the same findings: confirming both positives and negatives, which lends a great deal of credibility to the reliability and repeatability of this test method.

The future of food quality

The European Union has now launched a three-month program of testing meat products throughout the EU, which will certainly continue to feed the media circus. Testing protocols allow the use of the PCR DNA fingerprinting but also promote a protein-recognition method (Enzyme-linked immunosorbent assay, or ELISA) as a potential test for misrepresented meat. The result will be a rapid rise in acceptance for this type of testing for ensuring food quality.

As the investigations continue, it appears that at least some of this contamination resulted from deliberate mis-labeling of horse meat that had been properly labelled at its source -- raising the issue of where in the supply chain testing should be targeted. Already, farmers have raised concerns about the potential for added costs to prove that what they sell is what they say it is.

The breadth of products affected by these findings will certainly trigger testing in other countries as well. Although horse meat in not commonly butchered for food in the USA, as it is in parts of Europe, the addition of horse meat to beef products by deliberate deception makes anything possible.

Furthermore, the FSAI testing looked only for pig and horse meat contamination. What would we find if we started testing food for cat, dog, or rat? This question will raise the issue of detection limits and what levels of contamination can be accepted: dog and cat should presumably not be found, but one can imagine finding rat DNA in the product of any major food plant if the detection limits are low enough.

Finally, when food testing turns from safety to integrity, what do we do with the safe-to-eat foods that must be recalled due to ethical lapses? It has been announced that some of the recalled food will be "recycled" for heating value -- a disgrace in a world where people go to bed hungry. If the product is recalled for reasons other than safety, a mechanism must exist to make it available where the ethical issue does not pose a problem, perhaps by donation to food shelters where it can be distributed under full disclosure of the actual ingredients in this case.

See also: HIV-positive infant completely cured for first time

How do they find horse meat in hamburger?
A relatively new test detected horse meat in European hamburger. We wonder: how do they test this? Could it happen in America? What happens to all the recalled food?

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