Sunday, February 1, 2015
SpectroscopyNOW-Last Month's Most Accessed Feature: NMR spectroscopy rides in: Detects horse fat
The presence of horsemeat in adulterated meat products can now be revealed quickly and easily using nuclear magnetic resonance (NMR) spectroscopy to test the fat profile of the food without the need for complication and long-winded genetic analysis.
A team at the Institute of Food Research in Norwich, UK, have worked with Oxford Instruments to develop a fast, and inexpensive alternative to DNA testing for distinguishing horse meat from beef based on the profile of the meat's fat content.
Although both grass-eating herbivores, horses (Equus ferus caballus) and cattle (Bos taurus) have different digestive systems and as such the fatty constituents of the meat from these two species is rather different, providing a simple way to distinguish between the two in mislabelled or unadulterated meat products. NMR spectroscopy takes just ten minutes to distinguish between raw horse meat and beef and while initially funded by Innovate UK and the Biotechnology and Biological Sciences Research Council (BBSRC) has now been tested in an industrial setting at the premises of a leading meat processor. The team is now developing profiles for other meat fats, including pork and lamb.
Back in 2013 scandal rocked the food industry in the UK as it was discovered that food manufacturers and supermarkets were selling purportedly beef products in which horse meat had been used instead of beef. Millions of pounds worth of food was removed from supermarket shelves and the crisis brought urgency to understanding just how vulnerable the meat supply chain is to food fraud and perhaps threats to public health. High on the agenda was the lack of appropriate assays and tests other than slow and costly DNA testing.
The IFR and Oxford Instruments developed "Pulsar", a high resolution bench-top NMR spectrometer that is far smaller and a lot less expensive than conventional NMR spectrometers. Moreover, Pulsar is simpler to use and requires none of the sophisticated cryogenics for super-cooled magnets in high-power instruments. A meat test with Pulsar involved shaking approximately one gram of meat in an organic solvent and then a few minutes of data acquisition. The cheminformatics software that analyses the spectral lines and flags the sample as beef or horse was developed at IFR.
"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," explains Kate Kemsley. "It's been very satisfying to see results from a real industrial setting sit right on top of those we generated in our two labs. We think this testing method should work well at key points in the supply chain, say at meat wholesalers and processors."