It has been over three months now since Food Safety Authority of Ireland(FSAI) have discovered the circulation of horse meat on the Irish market. The FSAI study probe the presence of DNA from cattle, pigs and horses in Salamis, Beef Meals (e.g. Lasagna) and Beef Burgers. It has been highlighted on initial inquiries on two processing plants in Ireland and in the UK. Most countries in Europe were involved afterwards.
Moreover, with advancements on molecular biology, DNA ( Deoxyribonucleic acid) has become a very useful and an accurate instrument to assess the safety, quality and integrity of the food chain. It is the unique hereditary material in all cells, and is found in animals and plants and therefore in our food
Countries involved in Europe
According to reports, EU sources said a progress report from the EU’s executive dated April 9 showed that of 353 tests carried out in France, 47 tested positive for horse ( Equine ) DNA.
The progress report only included complete data for 11 EU countries, Greece had the second-highest level of positive results with 288 tests yielding 36 positive results – a rate of 12.5%. Germany found horse DNA in 29 samples out of 867.
In Great Britain, where horse meat has already been found in burgers and other products sold by retailers including Tesco, 150 official tests carried out as part of the EU-funded program returned no positive results for horse meat.
How is the testing conducted?
Three methods can be used for DNA testing namely:
- The most common method, PCR ( Polymerase Chain Reaction), involves extracting DNA from the food followed by amplification of specific pieces of DNA through an enzymatic process. The amplified DNA fragments are separated by size using a technique called agarose gel electrophoresis and are compared with DNA fragments of known size to enable their identification.
- In RFLP analysis, the DNA sample is broken into pieces by restriction enzymes i.e. enzymes that can recognize specific base sequences in DNA and cut the DNA at that site ( the restriction site). The resulting restriction fragments are separated according to their size using gel electrophoresis. RFLP analysis was the first DNA profiling technique inexpensive enough for widespread application.
- DNA barcoding is a molecular based system which is based on the analysis of a short genetic marker called the “DNA barcode” in an organisms DNA. By comparing the DNA barcode to a compiled database of barcodes it can be identified as belonging to a particular species. The success of the technique depends on (a) the molecular variability between species and (b) the availability of high quality repositories of reference sequences (i.e. DNA sequences of known species)
Is there a risk to consumer health?
It is pretty disturbing and appalling that in Europe where food control systems have gone through extensive review and yet a scandal of large proportions went unnoticed. The consumer’s confidence has been eroded thus far.
However, what is clear is the risk to public health from this incident is low since the horse meat used came from approved abattoirs. All meat that was tested for positive for horse DNA was proven negative for the anti-inflammatory drug phenylbutazone or “bute”.
Penalties or sanctions
Changes are being done accordingly. Global standards for the trade will become more stringent. As such, an increased penalty for those convicted of food fraud. Nevertheless, DNA testing of meat products will be standard for major retailers.