The mislabeling of meat products sold for human consumption has serious implications from a safety and ethical perspective. With recent news stories of pork and horsemeat contamination in different parts of the world, a renewed need for specialized testing of the food supply has rapidly arisen.
For Muslim and Jewish communities, in particular, it is critical for consumers to know whether there is even the slightest contamination of foods that are considered permissible to eat ('halal' and 'kosher'), having been prepared in accordance with Islamic or Jewish beliefs, respectively. To help serve the interests of these communities that together make up approximately 23% of the global population, scientists at the University of Münster, Germany, along with scientists from SCIEX, a global leader in analytical technology, have developed a new method for detecting pig and horse contamination of meat, including beef, chicken, lamb and others.
Major concerns about inaccurate, fraudulent or misleading labeling of meat-based products were raised during 2013 following numerous reports of horse and pig meat being detected, but not disclosed as contents, in beef-based products sold in supermarket chains across Europe. Moving forward, this new method from the University of Münster and SCIEX allows food testing laboratories to test products quickly and easily for trace amounts of pig and horse contamination.
"We are continuing our SCIEX tradition in partnering with experts in industry and academia to develop analytical tools that solve big problems," said Vincent Paez, Senior Director of Food & Environmental at SCIEX. "The halal testing method is a new tool that effectively addresses the safety, religious, ethical and dietary concerns of consumers who avoid products with pig and horse meat."
The new method, which was recently published in the Journal of Agriculture and Food Chemistry, uses liquid chromatography and tandem mass spectrometry (LC/MS/MS) to detect a number of biomarker peptides that are specific to pig and/or horse.
"Scientists in routine testing laboratories worldwide will now be able to use this method to detect and distinguish trace amounts of pig and horse in many food products," said Prof. Dr. Hans-Ulrich Humpf, Head of the Institut für Lebensmittelchemie [Institute for Food Chemistry], University of Münster.
As a leader in next-generation food testing technologies, SCIEX has previously developed similar methods for protein screening in food, including new techniques for detecting allergens such as eggs, milk, sesame seeds, nuts, and mustard simultaneously in food samples. Scientists at SCIEX are continuing to look into other similar areas of ethical concern, including detection of gelatin that has come from species such as beef and pork.
The new mass spectrometry-based method offers a more accurate and reliable approach to meat speciation than other methods. It can detect markers of multiple, different animal species in a single run vs. traditional methods, such as PCR or ELISA. These older, widely-used approaches detect the animal's DNA or intact animal proteins, respectively, but both of these approaches have limitations, particularly their lack of specificity, which can lead to false negative or false positive findings.
The new method was developed using a two-pronged LC/MS/MS approach, utilizing the TripleTOF® 5600 system first to identify the unique protein markers specific to a meat species, then utilizing the QTRAP® 5500 system to detect and confirm the presence of targeted meat peptides in unknown samples.
The QTRAP® 5500 system uses multiple reaction monitoring (MRM) to detect each peptide and is then capable of providing sequence information by acquiring a product ion scan for each triggered MRM, which can be used to confirm the peptide's identity.
"One of our goals was to develop a method that could be widely and routinely used by scientists in food testing labs, many of which have suitable mass spectrometry platforms," said Dr. Jens Brockmeyer, Research Group Leader at the Institut für Lebensmittelchemie, University of Münster. "We also wanted to raise awareness of the new possibilities of MRM3 experiments with the QTRAP System, which can significantly improve sensitivity and specificity."
Horse and beef protein markers may differ by as little as one or two amino acids, so it is important to have confidence in the results when distinguishing between species in food testing. The new method presents the first MRM and MRM3 method for rapid and sensitive detection of both species (down to 0.13-0.25%), using routinely available MS techniques.