New coffee testing method to deter fraudsters

Using the new technique, a survey of ground roast coffee samples labelled as 100% Arabica found that 10% of these coffees contained significant levels of Robusta coffee. 

The adulteration of Arabica with the cheaper, easier-to-grow Robusta has become an attractive possibility to fraudsters, claimed Quadram.

Using a benchtop NMR spectrometer from Oxford Instruments, Quadram can identify a specific chemical – 16-O-methycafestol (16-OMC) – found in the cheaper beans faster than traditional methods, speeding up the process from three days to 30 minutes.

Robust and portable​

The instrumentation is robust, portable and can be used by non-specialists, making it suitable for use in industrial situations, claimed Quadram. The method is sensitive enough to detect just 1% Robusta in an Arabica/Robusta blend.  

Kate Kemsley, who led the research at The Quadram Institute, said: “This is an important milestone for detecting fraud in coffee, as 1% is the generally accepted cut-off between trace contamination – which might be accidental – and more deliberate adulteration for economic gain.​

“It was immediately obvious, using our test, that there were several suspicious samples, producing results that were consistent with the presence of substantial amounts of Robusta – far more than would be expected through unavoidable contamination.”​

Above a certain threshold​

Due to the sensitivity of the new test, researchers found that Arabica beans do include low levels of 16-OMC, prompting them to stop testing for it presence and instead devising software to assess whether the level was above a certain threshold.

Commenting on the test, head of intelligence at the Food Standards Agency’s National Food Crime Unit Giles Chapman said: “We’re always keen to understand how scientific advances expand the range of tools which can be used to validate the authenticity of food products sold to UK consumers. ​

“This piece of work has generated some interesting insights, which we will be looking to explore further.”​

Chris Stemman, executive director of the British Coffee Association welcomed the new insights that the Quadrum Institute were able to provide.

“This is an important and easily accessible tool that could potentially be applied as an assurance measure along the coffee supply chain, so that authenticity can be checked and validated at all stages from farm to cup. ​

“Supply chain integrity remains a key priority for the UK coffee industry and we welcome further research that looks into this in further depth.”​​