Meat and fish fraud, such as beef being replaced with horse meat or cheaper fish being sold as premium fillets, can affect consumers worldwide. In addition to the financial consequences, mislabeling products can cause problems for people with allergies or religious restrictions. There are accurate methods to detect this fraud (e.g., based on the polymerase chain reaction or PCR), but they can be time-consuming.

Livia S. Eberlin, The University of Texas at Austin, USA, and colleagues have developed the so-called MasSpec Pen, a handheld device that rapidly extracts compounds from a material’s surface using a solvent droplet and then transports them to a connected mass spectrometer. The team used this device to effectively detect common types of meat and fish fraud in raw, pure filets and ground products.

The researchers used the MasSpec Pen to examine the molecular composition of grain-fed and grass-fed beef, chicken, pork, lamb, venison, and five common fish species. When the device’s tip is pressed against a sample, a 20-µL droplet of an acetonitrile/dimethylformamide (ACN/DMF) solvent mixture is released, extracting sufficient amounts of molecules for accurate analysis by mass spectrometry. The whole process takes 15 s, requires no preprocessing, and the liquid extraction does not harm the samples’ surfaces.

The team developed authentication models using the unique patterns of the molecules identified, such as carnosine, anserine, succinic acid, xanthine, and taurine, in pure meat types and fish species. Then, they applied the models to the analysis of test sets of meats and fish. They achieved very high accuracies in identifying the protein source at a much faster testing time than existing methods. According to the researchers, they plan to expand the method to other meat products and integrate the MasSpec Pen into a portable mass spectrometer for on-site meat authentication.

• Rapid Analysis and Authentication of Meat Using the MasSpec Pen Technology,
  Abigail N. Gatmaitan, John Q. Lin, Jialing Zhang, Livia S. Eberlin,
  J. Agric. Food Chem. 2021.
  https://doi.org/10.1021/acs.jafc.0c07830