|Meat substitution and fraud: FACTS optimises DNA screening method|
|Thursday, 21 February 2013|
While SA consumers may have nothing to fear from a horsemeat scandal currently rocking Europe, there is no such certainty when it comes to local processed meat. Species substitution is apparently rampant, according to a recent meat authentication study conducted by FACTS' food scientist, Dr Donna Cawthorn, that hit headline news in December 2012. A paper trail is of no value against this food fraud, says FACTS' Dr Harris Steinman, who has also announced that FACTS has recently optimised an animal species screening method which allows the detection of up to 24 different animal species in a single reaction, significantly reduce the costs and labour required to ensure product authenticity.
How sure are you that meat adulteration, i.e. any species that may be in your product which you may not be aware of has not affected your supply chain, asks Steinman. DNA screening for a range of meat species can eliminate doubt, he says.
In the latest FACTS newsletter, he writes:
It is no secret that the recent meat adulteration scandal has shaken the food industry over the last few weeks, presenting a plethora of new challenges to food manufacturers and compromising consumer confidence in the functioning of the meat supply chain, both locally and globally.
The shocking issue, which came to light on 15 January 2013, involved foods labelled as beef in the EU, which was found to contain undeclared horse meat, as well as other unlisted meats such as pork. Consequently, a number of big food industry names have been caught off guard. These include the UK supermarket chains Tesco, Iceland and Lidl, the German discounter Aldi, the frozen-foods processor Findus and the global fast food giant Burger King, all of which have all been implicated in marketing fraudulent meat.
Earlier this month, the EU commission approved plans to carry out random DNA testing on meat products throughout member states and 11 of the UK's largest food suppliers have declared that they are "working around the clock to complete the most comprehensive testing of processed beef products ever undertaken, anywhere in the world.”
What may have been largely overlooked in this case is that such meat adulteration scandals are not limited to horsemeat, and they are certainly not limited to the EU.
The meat authentication study conducted by FACTS food scientist, Dr Donna Cawthorn, that hit headline news in December 2012 when it was revealed that 68% of 139 processed meat products obtained from the South African market contained species not declared on the label, including undeclared pork, donkey, goat and water buffalo (see related publication). In a related story, the problem of species substitutions involving game meat served at local restaurants was simultaneously exposed.
• Butchers mislabel meats. Daily News, 10 December 2012.
While knowing your meat suppliers and auditing them regularly may be an obvious step in protecting the authenticity of meat products, in many cases food fraud cannot be discovered by following a paper trail and detection requires ‘state of the art’ scientific analysis.
Today, DNA-based techniques are considered the most appropriate methods for making species identifications as DNA is present and is identical in all tissue types, is relatively stable even at high temperatures and because the diversity afforded by the genetic code allows the differentiation of very closely-related species.
Over the past few years, FACTS has developed a large number of DNA-based methods for the identification of meat species, both in single ingredient commodities (using DNA sequencing) and in complex food matrices (using species-specific detection methods).
The detection of the compete substitution of a single meat species with another is one of the more simple scenarios for identifying food fraud. In general, DNA sequencing conducted on a queried sample will produce a DNA sequence or ‘fingerprint’ which can compared to a set of known reference sequences in a credible genetic database. The identity of the specimen can thereby be established, which is either the same or different to the one expected.
Investigating the partial substitution or adulteration of meat is considerably more difficult, since it is normally necessary to know the possible identity of the adulterant before it can be detected. To help alleviate these difficulties, FACTS is excited to have recently optimised an animal species screening method which allows the detection of up to 24 different animal species in a single reaction.
This method, which relies on the use of species-specific DNA probes to detect certain target DNA sequences, will significantly reduce the costs and labour required to ensure product authenticity.
Food fraud is indeed a food industry issue. Consumers are highly reliant on the accurate and complete declaration of food constituents to enable them to make product choices that are consistent with their lifestyles. Brand loyalty can be severely compromised should this be found not to be the case. As such, DNA testing can be of great value for the routine monitoring of meat product authenticity and should be conducted whenever a case of meat adulteration or contamination is suspected.