General Discussion

Large-scale international food safety scandals are known to be episodic. This year alone, these have included the export of expired or spoiled meat from 21 producers in Brazil to 61 countries, the pesticide fipronil in eggs affecting 65 countries to date, and the trial of those who conspired to pass off 30 tonnes of horsemeat as beef in Europe in 2013. Food fraud and counterfeiting can involve all types of food, feed, beverages and packaging, and has the very real potential for serious health, economic and social consequences.  Our latest research in this area, published in Scientific Reports, involves the non-contact through-container detection of counterfeit alcohol using handheld spatially offset Raman spectroscopy (SORS), used here for the first time in a food or beverage product.      

Spirit drinks are the EU’s biggest agri-food export, with EU governments’ revenues of at least €23 billion in excise duties and VAT, and approximately 1 million jobs linked to the production, distribution and sale of spirit drinks. An essential part of ensuring consumer confidence in this very important industry is to provide assurance that these products are authentic and have not been either adulterated or counterfeited. Importantly, sales of illicit spirit drinks not only have significant economic consequences, due to loss of trade and revenues, but they can also have serious health impacts when ‘denatured’ (i.e. industrial) alcohols or methanol are used by counterfeiters and unknowingly consumed, with multiple deaths reported worldwide. In the spirit drinks sector, counterfeiters often ‘recycle’ used genuine packaging, or employ good quality simulants. So in order to prove that suspect products are non-authentic ideally requires accurate and sensitive analysis of the complex chemical composition of a spirit drink while still in its packaging.

Researchers in the Manchester Institute of Biotechnology (MIB), with colleagues from the Scotch Whisky Research Institute (SWRI) in Edinburgh, Cobalt Light Systems in Abingdon, and the Science and Technology Facilities Council’s Central Laser Facility in Oxfordshire, have developed handheld SORS to detect fake spirit drinks whilst still in their bottles. These optical approaches where lasers are directed through glass, enable the isolation of chemically-rich information from deep within the contents of a container.  Nearly 150 samples of several well-known brands of Scotch Whisky, rum, gin and vodka in closed glass containers, including 40 simulated counterfeits were analysed blind using a handheld device, detecting multiple chemical markers known for their use in the adulteration and counterfeiting of spirit drinks worldwide. A total of 10 denaturants/additives were detected in extremely low concentrations (10 - 0.2ppm) without any contact with the samples. The researchers could also discriminate between multiple well-known Scotch Whisky brands, detect different levels of alcohol, and were able to detect methanol at 0.025%, well below the maximum human tolerable concentration of 2% (in 40% spirit drinks).  

Finally, in order to test if these methods could be used in commercial samples, several bottles of spirit drinks were bought ‘off the shelf’ from local shops. These were first measured unopened, then opened and adulterated with different levels of methanol (1, 2 and 3 %) and the tops replaced. Handheld SORS detected this adulteration with methanol through multiple colours (clear/brown/green) of commercial glass bottles in several types of spirit drinks (Scotch Whisky, gin, and vodka), again, well below the maximum human tolerable level in spirit drinks. Our open access article “Through-container, extremely low concentration detection of multiple chemical markers of counterfeit alcohol using a handheld SORS device”, can be found here: www.nature.com/articles/s41598-017-12263-0