New test successful in detecting fake coffee beans

A study published in the Microchemical Journal has confirmed that a new test can help discover adulterated coffee beans.

The study, called: Direct infusion electrospray ionization mass spectrometry applied to the detection of forgeries: Roasted coffees adulterated with their husks infusion found that direct infusion electrospray ionization mass spectrometry (ESI-MS) can be applied to show up counterfeit samples of roasted coffee contaminated by poor quality coffee husks in both a 'quick and reliable' way.

The ESI-MS fingerprints (in both the negative and positive modes) revealed diagnostic markers including: carbohydrates, chlorogenic acids, caffeine, and other components related to the coffee flavour, all of which characterise each type of sample (coffee and rusk).

The authors say that when an analytic approach was applied to the ESI-MS data (in the negative mode) they could group the samples into three clearly distinct categories: coffees, husks and blends and thus find the adulterated coffee beans.

The authors note that these results could prove to be an 'innovative and rapid methodology' that will be useful in the diagnosis of a difficult-to-detect type of adulteration.

It could also be an invaluable tool to the industry as the coffee bean market has become rife with adulteration and ‘filler’ in recent years, including adding ingredients such as corn, barley, wheat, soybeans, rice, beans, acai seed, brown sugar or starch syrup to coffee beans.

This has become a particular problem in Brazil, the world’s biggest provider of coffee, as a series of droughts and poor harvests have meant a large upscale of adulteration and filler entering into the supply chain to try and counteract dropping sales.

Another new test, highlighted at this year’s 248th National Meeting & Exposition of the American Chemical Society (ACS) held in August, uses liquid chromatography and statistical tools and is also seeking to develop a ‘characteristic fingerprint’ that separates out the real coffee compounds from the fake.

And these tests will need to be developed soon. As Suzana Lucy Nixdorf, research team leader for ACS explained at its meeting in August: "With a lower supply of coffee in the market, prices rise, and that favours fraud because of the economic gain."