Washington State University doctoral student Charles Diako collates documentation from readings of the ASTREE Electronic Tongue.
—When the wine starts talking, a new $90,000 device at Washington State University’s sensory evaluation lab in Pullman listens.
Acquired last year, the ASTREE Electronic Tongue developed by Alpha M.O.S. of Toulouse, France, gives WSU associate professor Dr. Carolyn Ross a new tool for assessing and analyzing the components of various food products.
Putting it to use
A current project is the analysis of 60 red wines from Washington state, and the correlation of results from the e-tongue with chemical analysis and the results of sensory analysis by trained tasters.
“We’re trying to see how well all of these chemical parameters, taken together, explained what our trained panelists observe in the wine,” she said. “The e-tongue will never replace people, but it certainly has use if you’re screening a lot of different wine samples. People get tired…and it’s hard to distinguish differences, especially if (the wines) are really astringent or they’re really high alcohol.”
The challenge is well-known, as underscored by the regular debates about the palates of wine judges (see “How Consistent Are Wine Judges?
One of the first challenges, however, was to determine what kind of information the instrument could provide and how to correlate this information with other ways of understanding wine.
Taste the rainbow
A broad selection of red wines was chosen to give the tongue the greatest latitude of tasting experience.
“We wanted differences among the wines. We were trying to find low-alcohol Merlots, high-alcohol Merlots, high-tannin/low-tannin ones that varied in the properties to see if the e-tongue could distinguish them,” Ross said. “We felt it would give a good indication of the way we could group the wines together.”
The result was the identification of six major groups arranged around characteristics such as tannins, alcohol content and metallic character.
While humans may be keen to perceive minerality, Ross said metallic notes are “part of the e-tongue profile.” (A previous experiment saw the e-tongue evaluate various sweeteners from sugar solutions to agave, Stevia and Aspartame, which is known for a metallic aftertaste.)
Since the device is in its infancy—one might say researchers have touched just the tip of the tongue’s capabilities—Ross hopes to expand the wine program to include white wines and sparkling wines so that a better understanding of the device’s use can be developed.
She also wants to see if the tongue can factor in and identify the differences that saliva type make to the sensory experience of wine.
WSU doctoral student Charles Diako has collated significant documentation regarding the e-tongue’s readings that will help researchers understand the tongue’s possibilities, but the challenge lies in putting that understanding to use.
“How can it be useful to the wine industry, to a large winery, to an academic institution?” Ross asked of the e-tongue.
Noting the significant investment the device requires, she says it’s not an investment many wineries will undertake lightly—nor did WSU.
However, the trials that WSU’s lab is undertaking are slowly sketching in details of the instrument’s capacity. As the old saying goes, life is too short to drink bad wine, and the tireless electronic tongue promises to help human testers focus their attention on wines that matter.
“We are the first group to use the e-tongue for the purpose of screening a large number of wine samples,” Ross told Wines & Vines
. It could “help reduce the number of samples that needed to be evaluated by a sensory panel.”