Chemist Kenneth Suslick of the University of Illinois at Urbana-Champaign and his colleagues have at least partially avoided this problem. Their idea: They did not try to determine every single component, but searched for a kind of fingerprint, which can be clearly assigned to each type of coffee. For this they developed their novel artificial nose. Its centerpiece is a polymer film, just the size of a small coin, on which the researchers placed dropwise 36 different dyes. The trick: Each of these dyes reacts to a different chemical property. For example, some of them change color depending on the pH level, others react only with certain substances, and yet others are similar to the red blood pigment hemoglobin and discolor only in the presence of a specific charged or uncharged particle.
The principle works, the scientists have already been able to show in ten commercially available coffee variants: When the plate came into contact with the coffee aroma, a different color pattern formed in each variety. Even if the individual device can not be determined with the new device? "The important thing is that we can easily see the differences between different roasts and coffees, " says Suslick. The potential of the new artificial nose could, according to "Science", go far beyond the recognition of coffees: It is conceivable to use practically everywhere, from the detection of explosives to the identification of impurities in toothpaste.Science, online service Original research by researchers: Kenneth Suslick (University of Illinois, Urbana-Champaign) et al.: Analytical Chemistry, online pre-publication, doi: 10.1021 / ac902823w ddp / science.de - Ilka Lehnen-Beyel advertisement