Video by Matt Haugen, WSU News

  

By Chelsea Pickett, WSU News writing intern

 

PULLMAN, Wash. – An “electronic tongue” at Washington State University is hard-wired to taste wines in a way that humans cannot.
Unlike human taste buds, the e-tongue never tires or takes a day off, even after hours of around-the-clock sampling, said Carolyn Ross, assistant professor of food science who runs the sensory evaluation lab.
Ross is evaluating wines produced in Washington, the state second in premium wine production. Working with Ross is Ph.D. student Charles Diako, originally from Ghana, who is a super-taster himself.
He appears to have met his match in the e-tongue; together, they’re a complementary tasting team. While the e-tongue interprets data by using biosensors and statistics, Diako uses his taste buds and brain.
“The e-tongue gives an objective measurement of taste profiles and we try to correlate that to what happens in human sensory evaluation,” he said.
Automatic wine taster
The e-tongue works by dipping its “tongue” into a beaker filled with wine on a rotating platform called an autosampler. It reads a profile of sensory attributes ranging from metallic and savory to sweet and bitter. After the tongue pulls out, the platform turns to present the next beaker of wine.
While humans can detect flavor attributes, the e-tongue identifies taste compounds at the molecular level, said Ross.
What’s more, human taste buds can get saturated and lose their keen ability to accurately distinguish taste features, whereas the e-tongue never gets fatigued.
But that doesn’t mean human taste testers and sommeliers will find themselves out of work. Many companies and institutions, including WSU, use tasters – some volunteer, some professionally paid – to sample products and provide feedback that fine-tunes the development process.
“Human evaluation is more sensitive and integrates a huge amount of information and perception in response,” said Ross. “This technology won’t replace human evaluation.”
For example, the e-tongue might be able to give some information about the mouthfeel of a wine, but it isn’t designed to do this, she said. A wine’s mouthfeel provides sensations of physical and chemical interaction to the human palate, often described in terms like tannic, aggressive or chewy.
“The human tongue is the primary taste organ of the body,” said Diako. “Being a living tissue and being integrated with the most sophisticated computer the world has ever known – the brain – its perception of taste is absolutely matchless.”
Flesh-and-blood wine taster
Just like pairing a good wine with the right cheese, the new e-tongue has been paired with the right scientist. Diako joined Ross’ lab a year ago, shortly after WSU purchased the e-tongue to assist the university’s expanding role in Washington’s wine research.
While there’s no way to know if the e-tongue enjoys its work, it’s clear that Diako loves what he does in the lab. Always smiling and often laughing, when he came to WSU he knew little about wine or e-tongue technology, he said.
“I didn’t even know there was a difference between Washington state and Washington, D.C.,” he said.
But he does know sensory science and, now, what makes a good wine. His research history includes work on aromatic rice, considered important in his native African country where rice is a staple food. He plans to apply his expanded sensory skills to the research and higher education needs of his country upon returning home.
“I love research. I love teaching,” he said.
Diako is often sought out by lab members for his ingrained expertise at detecting precise tastes. Advanced taste sensitivity is often genetic and he was born with finely-tuned taste buds, he said: “You need that to be able to work in this field.”
Raising a glass
The sensory lab is evaluating 60 red wines from Washington and plans a follow-up study on the same number of state-produced white wines.
“The use of the e-tongue for assessment of this many red wine samples hasn’t been undertaken before,” said Ross.
The information gathered from the evaluations is important to the Washington Association of Wine Grape Growers for guiding fruit and vineyard management, said Diako. After all, a great bottle of wine begins in the vineyard.
Will the e-tongue know if that bottle is, in fact, a good wine?
Absolutely, by providing it with a gold standard, said Diako, adding with a smile, “But it doesn’t know the price.”