NMR spectrometer detects meat species

Having collaborated with Oxford Instruments, the high-resolution benchtop nuclear magnetic resonance (NMR) spectrometer looks at differences in the chemical composition of the fat in horse and beef meat - employing similar technology to a hospital magnetic resonance imaging (MRI) scanner.

Fat present in the food we consume is often in the form of triglycerides - molecules containing a short ’backbone’ of carbon atoms to which ’fatty acids’ are attached, the Biotechnology and Biological Sciences Research Council (BBSRC), who helped fund the test, said.

“It’s a stroke of luck really that some of the most important meats turn out to have fat signatures

IFR scientist Kate Kemsley

According to the BBSRC, fat from horse meat contains many more poly-unsaturated chains than the fat from beef, for example.

Therefore, measurement of the fatty acid composition by proton NMR provides a ’fingerprint’ by which the species of the sample can be identified, the BBSRC said.

Utilising the NMR spectrometer, a technician can perform the necessary analyses within 10 minutes and determine whether a piece of raw meat is horse or beef.

The test is currently being expanded to understand whether a meat species is pork or lamb.

The Pulsar DNA test kit is based on permanent magnets, as opposed to super-cooled magnets in more conventional instrumentation, and is designed to screen meat species quickly and cheaply, the IFR said.

The IFR team discovered that a couple of minutes shaking roughly a gram of meat in a solvent followed by a few minutes of data acquisition on Pulsar were enough to tell horse meat from beef.

“It’s a stroke of luck really that some of the most important meats turn out to have fat signatures that we can tell apart so easily with this method”, said Kate Kemsley, head of the scientific support unit at the IFR.

We think this testing method should work well at key points in the supply chain, say at meat wholesalers and processors,” she said.

Software which carries out mathematical analysis of the spectral data has also been developed at IFR.

According to Kemsley, the NMR test has an advantage over more traditonal testing methods such as Polymerase Chain Reaction (PCR) as ’fat fractions’ can be easily extracted by anyone with minimal training, and accurately tested within 10 minutes.

“This means that for the same outlay of cost and time, more high-throughput testing is possible compared with biological methods,” Kemsley said.

However, Kemsley did admit that the NMR system can struggle to deal with mixtures of meats with grossly different fat contents, or with complex, processed, food products.

“For these types of samples, the sensitivity of PCR testing would still be needed,” Kemsley said.

“At the moment, our system is designed to work on whole blocks of [frozen] meat trimmings, as found earlier in the food production chain.”