DNA-based identification system ensures meat traceability

So just where is the beef? Animal and meat traceability systems may be in place, but just how effective are they? Stephen Leese reports.

Consumption of beef in most European countries has almost returned to levels achieved prior to the BSE crisis of 2000. And this despite a slightly higher retail price per kilo. So what does this tell us? Is the crisis over? Can we relax and return to the ideal of buying beef because we enjoy it, without having to worry about its safety?

Some would say not, since there are still new cases of BSE in Europe being recorded almost on a weekly basis. In Japan and Canada, first instances of BSE have been recorded in 2003, despite elaborate control mechanisms being in place. These cases, however, no longer appear in the popular press and so the consumer fails to pick up this information.

In America, the Country of Origin Labelling programme­ strangely referred to as COOL ­ has been signed into law as part of the 2002 US Farm Bill. The labelling provision requires that all fruits, vegetables, peanuts, meat, and fish be labelled on grocery store shelves by country of origin starting in September 2004. Initial calculations estimate that this program will cost the food industry in the United States around US$1.9billion to implement. However, certain other market research studies find that American consumers are willing to pay an additional US$3.1billion for origin labelling of ground (minced) beef alone.

Labelling goes a long way towards allaying the fears of consumers when it comes to the source of the steak being served up at home. But just how fool-proof are such systems?

The paper-based systems in place across Europe are intended to ensure that the relevant authorities know the movement history of cattle from birth through to the meat counter. This is important for the purposes of product recall and product liability claims. However, when such huge volumes are moved on a daily basis, mistakes will inevitably be made. The system is also open to abuse, in particular since considerable amounts of money are involved. Some estimations suggest an incorrect labelling rate ­ for whatever reason ­ of up to 15percent. In other words, as many as one in seven labels might not give the correct information concerning the meat contained in the package

In recent years, there has been significant progress to utilise modern laboratory techniques to support traceability particularly of meat products. The use of DNA analysis for identification purposes is no longer confined to the crime investigations shown on the increasingly popular television series. Today, the cost of a DNA analysis in laboratories across Europe has been reduced to a level, which makes its application viable even in a low margin sector such as Agriculture.

The problem so far has been to obtain adequate samples for such testing, without making the whole process uneconomical. Currently samples of blood, hair or tissue are taken from live animals and stored for later analysis. The costs associated with these types of samples are shown in Table 1.

Blood samples are effective but expensive due to the requirement for a vet to take the sample. Hair samples are often placed in plastic bags or simply stuck onto reference cards and sent to the laboratories by post. The condition of some of these samples renders them useless and the risk of contamination or incorrect registration is extremely high. The risks associated with the types of samples taken are shown in Table 2.

These risks can be minimised by using a system such as that developed and patented by Biopsytec. A tissue sample is taken automatically when an identification ear-tag is placed on the animal, thereby ensuring an unequivocal link between animal and sample. Standard caps are used to retain the tissue sample, allowing high throughput analyses in most laboratories, helping to keep the logistical costs to a minimum.

A second reference sample is then taken either at slaughter or from a piece of meat at the counter and matched up with the original sample, thereby theoretically proving its origin, or at least confirming what is stated on the label.

Currently, politicians and food organisations are still wary of using DNA analysis for animal identification purposes. They fear the high cost associated with such testing. We have calculated however, that since not every piece of meat needs to be tested ­ a spot-check rate of between 5­10percent is adequate to ensure the quality control system works ­ the additional cost for meat purchased over the counter is in the range of a few cents per kilo and is less than current market price fluctuations ­ in other words, these costs would not be apparent to the consumer.

Consumers in Europe at least seem to have some confidence in current meat labelling procedures; otherwise consumption would not have recovered as it has. Just how well placed this confidence is will be tested by the next meat scandal ­ which is bound to occur. Maybe then the use of modern laboratory techniques for traceability purposes will become standard practice.

Enter 32 or at www.scientistlive.com/efood

Stephen Leese is a director of Biopsytec based in Rheinbach, near Bonn, Germany. www.biopsytec.de

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