Intelligence on undeclared meats shared
At a time, when the food industry is being encouraged to conduct sampling, testing and supervision of food supplies at all stages of the supply chain; the actions of one of the major food retailers, to share all findings from their own investigations should be applauded. It puts the needs of consumers before all others. Furthermore, in the Elliott Review Final Report published last month ‘Intelligence Gathering’ is one of eight integrated recommendations of the report, which also highlights the important role of analysis. It is understood that the retailer’s own DNA surveillance found that five products on their shelves contained undeclared meats (chicken, turkey and lamb DNA was detected), believed to be as a result of adventitious contamination from cross-over. It has been reported in the press that there was: up to 5% undeclared chicken and turkey in a pork sausage product; chicken DNA present in turkey slices; between 5 and 30% lamb in venison burgers; between 1 and 5% chicken in turkey and pork sausage slices; chicken and turkey DNA in a pork and beef sausage. Such incidents illustrate the importance of effective process controls and both the capability and limitations of analysis. The current analytical PCR approaches used detect species-specific DNA which, whilst helpful in identifying the undeclared meat species, can only estimate the levels present semi-quantitatively and this can be compromised by the degree of processing. In the two ranges of PCR kits offered by Bio-Check, up to 18 different species can be detected using a combination of end-point detection and real-time PCR techniques. Whilst most are single species tests, some species can be detected together in a duplex reaction, which saves time. When testing complex and processed foods it is important to understand the capability of the PCR test to ensure it will be suitable. For example, single species detection of goat by the real-time method offered by Bio-Check detects a 96bp fragment which allows detection in highly processed products, plus the method is performed as a duplex reaction with an inhibition control to ensure reliable quantification at a limit of 0.1%