PCR-based food testing to grow at a CAGR of 11% through to 2016

During the past three decades since its invention, the polymerase chain reaction method (PCR) has become a fundamental method for analysis in life sciences. While developed countries still dominate the PCR market, emerging markets are showing strong growth trends. 

A September study from Acubiz Consulting titled The Asia Pacific Markets for PCR Technologies identifies market dynamics in various countries in the Asia Pacific (APAC) region and forecasts the potential of the market related to product segments, technology segments, and end-use segments. 

The global demand for PCR was around US$10.6 billion in 2013. Even though North America had the highest market share in 2013, the Asia Pacific region is forecast to grow at a CAGR of over 11% between 2013 and 2018.

The application segments of this platform are still expanding, driven by the expiry of key PCR patents. The rising investments in the field of companion diagnostics have also been boosting the demand for PCR. Food safety testing is another significant end-use segment of the technology, driven by both consumer demand and regulatory requirements. Identifying the animal origin of meat products is another application.

Companies featured in this report include Abbott Laboratories,
Arachem, Cepheid, Fisher Biotec, KogeneBiotech and Seegene.

New tests for contaminated meat are more sensitive than ever

Scientists are experimenting with new tests based on the original polymerase chain reaction (PCR) to identify the animal origin of various meat products, and coming up with increasingly accurate results. While ELISA and PCR are the typical methods used to determine meat contamination, they may be more expensive, slow; require special equipment, technicians with specific skills, or have limitations to their sensitivity and specificity. 

Better tests are needed because of the possibility that a product claimed to be from one animal could well be adulterated with meat from another: an experiment reported in January 2014 in the Journal of Food Science Technology, for example, analysed 224 meat products using PCR and PCR-RFLP* and found that 7.58% of the samples actually contained haram (unlawful or forbidden) meat. Similarly, a study from the Asian Australasian Journal of Animal Sciences published October 2014, also using PCR-RFLP, showed that nearly half (45%) of all meatballs from the local market in the Yogyakarta region in Indonesia suffered from pork contamination, although meatball shops in the Surabaya region were free of it. 

In February 2014, Food Chemistry published an experiment on detecting the adulteration of meat products with pork with another PCR method, the assay of mitochondrial D-loop. The method worked for raw, cooked (at 60, 80 and 100°C), autoclaved (121°C) and microwave-oven processed pork, and could detect as little as 10 picograms (a picogram is 10^-12 of a gram) of pork in meat from other species. 

Another PCR assay, for dog meat adulteration, was described in Meat Science in August 2014. A blind test, one where researchers cannot tell the origin of the samples, showed that the method can reliably detect as little as 0.04 nanograms (a nanogram is 10^-9 of a gram) of dog DNA mixed in with chicken or beef meatballs. 

Another method was described in the Journal of Agricultural and Food Chemistry, published in October 2014. A method that combines liquid chromatography with mass spectrometry (often referred to as HPLC-MS) provides fast, sensitive detection of horse and pork in highly processed food. As little as 0.24% pork or horse in beef could be detected, even if the meat had already been cooked, with the samples ready for testing in 2 minutes.

*RFLP stands for restriction fragment length polymorphism.

Halal testing kits to get faster

The University of Selangor is working on a kit that can determine if tested material is halal within a minute. Nanosensor technology will be deployed to determine if the food, medicine or cosmetics has up to 0.001% of pig content, said Unisel Vice Chancellor, Prof Dr Anuar Ahmad in a 1 July report cited in Selangor Kini.

The kit, which is only to be available in December 2015, could be of use to Muslim consumers, food, medicine and cosmetics manufacturers in addition to certification bodies.

Existing halal testing typically makes use of polymerase chain reaction (PCR) or enzyme-linked immunosorbent assay (ELISA) methods. Profound Kestrel Labs has the PKL PorcineTrace PCR kit, which enables detection of porcine DNA down to 5 pg of porcine DNA traces in food products within approximately 3-4 hours (excluding the DNA extraction process). Its PKL Porcine qPCR Detection kit utilises a slightly different PCR method to come up with results in two hours, excluding DNA extraction.

Perkin Elmer, which already offers a halal testing kit called the Porcine Detection Kit for raw and processed meats, has created a table comparing current methods for determining if material is halal. The company's kit uses immunochromatography, and can complete tests in 20 minutes, with 0.005% accuracy. The company notes that tests were only done on up to 0.005% concentrations and the kit could well detect pork at even lower concentrations.

Source: Perkins Elmer website.

In January this year, analytical technology firm AB SCIEX announced that its scientists, together with scientists from the University of Münster, Germany, had developed a new method for detecting pig and horse contamination of meat, including beef, chicken, lamb and others. The company had 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. 

The new mass spectrometry-based method offers a more accurate and reliable approach to identifying meat species than other methods, AB SCIEX said, and can detect markers of multiple animal species in a single run whereas traditional methods such as PCR or ELISA can lead to false negative or false positive* findings. 

"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 in a release from the company in January.

Scientists at AB 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. An experiment conducted by AB SCIEX has shown that a gelatin ingredient can be extracted and analysed in less than 1 hour and a 1% impurity of pork in beef gelatin can be detected. The method can be used to detect the origin of gelatin that is found in sweets or medicine.

*False negatives claim that the test is negative when it is not. In a test checking if a beef sample contains pork, a false negative would say there is no pork when it actually exists in the meat. A false positive claims the test is positive when it is not. In a test checking if a meat sample contains pork, a false positive would show that there is pork in the meat when there is actually no pork.