London, Feb 16 : The coffee industry might just bid adieu to expert coffee tasters, for researchers have devised a new mechanical method to assess the flavour of the beverage.
The researchers used a device called mass spectrometer to measure levels of compounds specific to a particular aroma in different types of coffee, and found that they could predict about flavours that nearly converged with the opinions of a panel of trained tasters. The breakthrough development by Christian Lindinger of the Nestle Research Centre in Lausanne, Switzerland, could prove to be useful to the 2.2 billion pounds per year UK coffee industry, but a bad news for the approximately 50 human "coffee cuppers", or tasters, employed to ensure brands consistency of quality and flavour.
"This study aimed to give an answer to a fundamental question of flavour science: Can a machine taste coffee? We demonstrate that this is indeed possible. Until now it has always been less effective to ask humans to taste it. Machines will never completely replace humans in this role as the fine tuning will always have to be done by tasters. However I think it will be possible to use machines to detect for obvious defects," the Telegraph quoted Lindinger, as saying.
Lindinger questioned trained coffee experts to assess 11 types of coffee on the score of 0 to 10 for the strength of each of 11 aromas - coffee, bitter, cocoa, roasted, woody, cereal, butter toffee, acid, citrus, wine and flowery.
It is believed that coffee can give off almost 1,000 volatile compounds, but its flavour is influenced by just 50 of these compounds.
Using mass spectrometer, the researchers tried to identify the levels of 30 of the key compounds in the air above a cup of each type of coffee. This enabled them to establish the chemical patterns associated with the specific 11 aromas.
After repeating the exercise with eight new types of coffee, it was found that the aromas predicted by mass spectrometry analysis came close to matching the analyses of the human testers.
Still, Mike Reily, head of coffee at Taylors of Harrogate, was doubtful that he and his colleagues could soon be seeking alternative employment.
"Ultimately the assessing of coffee is a totally human activity. A machine might be able to tell you that particular chemicals are present, but for me it is about identifying a balance of different aromas that sit well together. I'd be very surprised if the industry moved towards widespread analytical rather than human testing," he said.
The study is published in the journal Analytical Chemistry.