Artificial nose can distinguish between coffee brands

Feb 19, 2010 by Lin Edwards report
Coffee

(PhysOrg.com) -- A team of chemists led by Ken Suslick from the University of Illinois in Urbana-Champaign, have developed a coffee analyzer than can distinguish between ten well-known commercial brands of coffee and can also make a distinction between coffee beans that have been roasted at different temperatures or lengths of time.

Scientists have been trying to develop an analyzer for coffee for some years, but the task is complicated by the fact that the aroma of roasted coffee beans is derived from over one thousand compounds, many of which change with the temperature and time of roasting. Many of the compounds are also similar to each other, which makes distinguishing between them difficult for methods such as gas chromatography (GC) and (MS), and also for sensors that change chemical properties or colors when exposed to the compounds.

The new analyzer is a variation on the , and uses 36 dyes, each of which interacts strongly with a specific compound. The pigments within the dyes include pH indicators, and metalloporphyrins, which are a class of strongly colored pigments to which and hemoglobin belong. Droplets of the dyes are placed on a about 1 cm across and then exposed to the coffee vapors.

The volatile compounds in the coffee aroma produce different colors as they interact with the dyes, and Suslick and his team found that different brands of coffee, and coffee roasted under different conditions produced unique color patterns.

The coffee analyzer may help coffee growers determine cheaply, and almost instantly whether batches of coffee are as good as previous batches, or whether problems such as burnt flavors exist in the batch. Variations on the device could also find uses in a wide range of applications such as detecting contaminants in toothpaste or sniffing out explosives. The report on the analyzer appears in this month’s edition of .

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More information: Discrimination of Complex Mixtures by a Colorimetric Sensor Array: Coffee Aromas; Benjamin A. Suslick, Liang Feng and Kenneth S. Suslick; Anal. Chem., Article ASAP. DOI:10.1021/ac902823w

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fourthrocker
3 / 5 (2) Feb 19, 2010
This means that it can also distinguish between brands of charcoal like Kingsford and Starbucks. Starbucks is a brilliant scam. If you over roast coffee beans it removes all the character of the bean and makes the cheapest beans taste the same as the best. No need to buy good beans then, just convince people that 'dark roast' is good. It's easy to tell a good roast from a bad, coffee beans that are roasted properly are brown, not black and all Starbucks coffee is over roasted to black. Evidently they have been somewhat successful. Amazing how many people have no taste and think dark roast tastes good. Seems like a direct correlation to how many stupid people there are, no shortage. In fact I would bet that most people who don't believe global warming like dark roast and Starbucks coffee. Some of the best coffee is also the cheapest, regular roast 8 o'clock is excellent, so is Gevalia.
plasticpower
not rated yet Feb 20, 2010
I'm sorry, but how is having a taste preference "stupid"? Around this area we have Starbucks along with a few other big coffee chains, and people prefer Starbucks because of how their coffee tastes, not because they are "stupid".