Determining the presence of undeclared animal species using Real-time PCR in canned and ready-to-eat meat products in South Africa

DNA based PCR is the most widely used technique for the detection of animal species in processed meat products. However, the detection of animal species in highly processed meat products, specifically, canned meat, has been reported to be challenging due to the presence of highly degraded DNA and/or the inability to extract sufficient amount of amplifiable DNA. The aim of this study was to evaluate the use of Real-time PCR to detect animal species in ready-to-eat meat products which represent highly processed complex food matrices. DNA was extracted from a total of 44 ready-to-eat meat products purchased from supermarkets in South Africa. The extracted DNA was screened for the presence of commonly reported undeclared animal species using Real-time PCR. Real-time PCR successfully detected the animal species declared on the product label, thus demonstrating its suitability for highly processed complex food matrices. Undeclared animal species was detected in 27% of the meat products tested in this study. Surprisingly, four products marketed with a specific "no-pork" claim tested positive for pork. An additional eight products tested positive for undeclared chicken, beef and/or sheep. The presence of undeclared animal species indicates a need for food authenticity monitoring. In cases where it may not be practically feasible to prevent the adventitious presence of unintended animal species despite adhering to the highest standards of production, it may be advisable for manufacturers to implement precautionary labelling. The use of precautionary labelling for animal species in processed meat products is a new concept that requires further consideration.