A professor of molecular cell biology has weighed in on the adulterated meat case in Britain and Ireland, asking whether the discovery of horse DNA in beef burgers had actually been proven to be “meat”.
Professor Ellen Billett, from Nottingham Trent University, was commenting following publicity around the Food Safety Authority of Ireland (FSAI) findings in a targeted study which examined the authenticity, or labelling accuracy, of a beef burger, beef meal and salami products available from retail outlets in Ireland.
In particular, the survey investigated the presence of horse and pig DNA in products.
It was reported that the study “revealed the presence of horse DNA in some beef burger products”.
Of particular concern was the fact that one burger reportedly contained 29 per cent horse DNA relative to beef DNA, which is claimed to indicate that “horse meat accounted for approximately 29 per cent relative to the beef content.”
While the story is obviously of public concern, public health issues may not be involved, Billett said.
“What is clear is that customers are being misled by the product labels and it appears that retailers are being let down by suppliers, as noted by Professor Alan Reilly, Chief Executive, FSAI.
“Of most interest are the methods used in the survey,” Billett said.
“The FSAI report clearly stated that the analyses involved detection of DNA, but subsequent discussions have assumed that the presence of DNA of a particular species correlates with the presence of meat from that species.
“According to strict food labelling legislation, the meat content of a product refers only to skeletal muscle and undeclared blood and offal – organs such as heart, liver, lung and kidney – is not permitted.
“What may not be realised is that, since DNA is the same in all organs/tissues, DNA-based detection methods cannot distinguish between meat and other organs/tissues.
“Thus, the claim that 29 per cent horse ‘meat’ is present in one of the burgers has not been substantiated. In other words, other horse organs/tissues may be present.
“Of further interest is that John Humphrys, when introducing Professor Patrick Wall, Professor of Public Health, University College Dublin, on the Radio 4 Today programme [recently], indicated the surveillance was conducted because offal was suspected to be present in the samples. This begs the question – is offal present?
“Although DNA-based methods cannot distinguish between organs/tissues, the good news is that tests are available to detect the presence of various offals and added blood in meat products. These tests have been developed over a number of years by the Food Authenticity Group at Nottingham Trent University, partly funded by the Food Standards Agency and the Department for Environment, Food and Rural Affairs.
“The tests are based on the detection of specific proteins which distinguish between skeletal muscle and heart, liver, blood etc and can be used on both fresh and processed foods.”
Billett said the Nottingham Trent University group would welcome the opportunity to apply their tests to establish the identity of the horse tissue/organ present in the burger containing the highest level of horse DNA, and to test for the undeclared addition of offal and blood in other products.
Meanwhile, the chairman of Ireland’s ABP Food Group, which owns two of the plants where products containing horse DNA were detected, says he is “disgusted” by what he calls the tabloid sensationalism around the story.
Larry Goodman told the Financial Times: “We are talking about DNA testing and DNA will pick up molecules and something in the air.
“I would not be surprised if there was not cross-contamination of various species if one were to do DNA testing.”
The three plants involved – two in Ireland and one in Britain – have implicated suppliers of filler products from the continent as the source of the contamination.