A new method to identify unwanted animal products in minced beef has been developed by researchers at the University of British Columbia.
Food science students led by Professor Xiaonan Lu used a laser-equipped spectrometer and statistical analysis to determine with 99% accuracy whether ground beef samples included other animal parts.
Moreover, they were able to say with 80% accuracy which animal parts were used, and in what concentration in a study published in Scientific Reports.
The new method can accomplish all of this in less than five minutes, they claim, which makes it a potentially transformative food inspection tool for government and industry.
“By using this innovative technique, the detection of food fraud can be simpler, faster and easier,” said the study’s lead author Yaxi Hu.
DNA testing has proven efficient and accurate in identifying foreign species in meat products, but what DNA testing cannot do is identify offal mixed in with meat of the same species.
To establish their method, the UBC researchers aimed a spectrometer at meat samples they had prepared by grinding together beef and offal from local supermarkets at various concentrations.
Because animal products all have different chemical compositions, their molecules absorb and scatter energy from the spectrometer’s laser in different ways.
The spectrometer captures these signals—or spectra—to produce an “image” of each substance. These spectral images can serve as a library for comparison with other samples.
Whether a meat sample is authentic or adulterated with offal can be determined by comparing its spectral image with the pre-established library, to see if there’s a match.
The method improves on existing techniques that are more complicated and time-consuming.
For example, a technique known as liquid chromatography works well, but it requires meat samples to be liquefied with solvents before testing, which can take more than an hour.
“The instrumentation for this technique is not that complex,” Hu said, “so, if government or industry wants to do some rapid screening, they don’t need to find highly trained personnel to conduct the experiment.”
All they would need is a spectrometer and user-friendly software that connects to a robust library of spectral images. As more types of meat and offal were analysed and their results stored, the technique would become even more accurate.
The researchers’ ultimate goal is to create an affordable smart device that could be used by consumers at home for the authentication of different food products, much like the pregnancy-test strip.