New Electric Tongue Evaluates Washington Wines
An “electronic tongue” at Washington State University is hard-wired to taste wines in a way that human tongues cannot.
Unlike human taste buds, this so-called “e-tongue” never tires or takes a day off, even after hours of around-the-clock sampling, said Carolyn Ross, associate professor of food science and viticulture and enology, who runs the sensory evaluation lab on the Pullman campus.
Ross is evaluating wines produced in the state of Washington, which is the second largest producer of premium wines in the United States. Working with Ross is her Ph.D. student, Charles Diako, originally from Ghana, who is a super-taster himself.
Diako appears to have met his match, though, working with the e-tongue to evaluate Washington wines.
While humans can detect flavor attributes, the e-tongue identifies taste compounds at the molecular level, said Ross. “The e-tongue gives an objective measurement of taste profiles and we try to correlate that to what happens in human sensory evaluation,” said Diako.
Automatic Wine Taster
The e-tongue works by dipping its “tongue” into a beaker filled with wine on a rotating platform called an autosampler. Then it reads a profile of sensory attributes ranging from metallic and savory to sweet and bitter. After the tongue recoils from the sample, the platform turns to present it with the next beaker of wine.
While human taste buds can get saturated and lose their keen ability to accurately distinguish taste features, 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 professional and 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 perceptions in response,” said Ross. “This new 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, said Ross. A wine’s mouthfeel provides sensations of physical and chemical interactions among the human palate, often described in terms like tannic, aggressive or “chewy.”
And while the e-tongue interprets data by using biosensors and statistics, Diako uses his taste buds and brain. “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 as fortuitous as pairing a good wine with the right cheese, the new e-tongue has been paired with the right scientist. Diako joined Ross’s lab a year ago, shortly after WSU purchased the e-tongue for its 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, Diako knew little about wine or e-tongue technology when he came to WSU, he said.
“I didn’t even know there was a difference between Washington the state and Washington, D.C.,” he said, throwing his head back in laughter. But he does know sensory science and, now, what makes a good wine. Diako’s research history includes work on aromatic rice, an important staple food in his native African country. Diako plans on applying his expanded sensory skills to the research and higher education needs of his country upon returning home.
“I love research. I love teaching,” he added.
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 state, including a planned follow-up-study on the same number of Washington-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 grape growers and winemakers to guide fruit and wine flavor development, said Diako. After all, a great bottle of wine begins in the vineyard. Will the e-tongue know if that bottle does contain, 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.”
Learn more about WSU sensory science and research at http://sfs.wsu.edu/sensory/ or visit wine.wsu.edu.
Wine Down Under
Join Thomas Henick-Kling, the director of the WSU Viticulture and Enology Program, on an incredible vineyard and winery tour of Australia, March 30 through April 15, 2014.
Travelers will experience insider tours and tastings with more than 20 winemakers. Together, they’ll visit Yarra Valley, Mornington Peninsula, Tasmania, Coonawarra, Adelaide Hills, Barossa Valley, and McLaren-Vale. Enjoy the scenery and wildlife along the Great Ocean Road, one of the most scenic coastal drives in the world.
Henick-Kling spent a total of six years in Australia, first as a graduate student in Adelaide and later as director of the National Wine and Grape Industry Centre at Wagga Wagga. He will take tour members to meet with some of the industry leaders he knows well and also meet with emerging innovators.
For the full itinerary visit: http://bit.ly/17PjR8w.
Lost in Transportation: Where Do Sugars Go?
Grapes have a circulatory system that is not so different from the one in the human body. Both are responsible for promoting healthy growth by shuttling valuable nutrients to and from cells. And in grapes, the systems that deliver valuable sugars and water can make all the difference when it comes to proper maturing and ripening.
For grapes, the logistics are critical: sugar molecules that help wine grapes ripen and acquire a sweet taste need to “find a ride” across every cell’s bag-like membrane and into the body of each cell.
Yun Zhang, a research viticulturist at WSU Irrigated Agriculture Research and Extension Center (WSU-IAREC), is learning more about this “ride” sugars take, with her research on genes that prescribe proteins, called sugar transporters, that shuttle the sugar molecules across cell membranes. She spent three months in France at the Institute of Vine and Wine Science in Bordeaux, looking at the genetic blueprint of sugar transporters in grape pedicels (the tiny stem that connects the berry to its cluster framework).
She wanted to know whether there is a mechanism in the pedicel that could help retrieve any sugars that might potentially escape via the grape’s water pipeline called the xylem. Her visit was made possible by a travel grant from the University of Bordeaux and by funds from WSU’s Viticulture and Enology Program.
Getting Back to the Backflow
Where humans have veins and arteries, plants have xylem and phloem. They each serve different purposes. The xylem is a plant’s water pipeline, moving water up through the plant’s roots and into the leaves and fruit, to help grape develop. The phloem, by contrast, moves sugar and other nutrients around the plant, pumping it from the sugar-producing leaves into the sugar-accumulating berries. That sugar is dissolved in water, though, so the two end up in the berries together. To permit sugar storage while maintaining proper pressure inside the grape, water “backs out” of berries through a recycling process Zhang refers to as xylem backflow. The prevailing thought is that grape berries are efficient at retaining the valuable sugars they need for ripening, but scientists at the WSU-IAREC suspect that berries might lose sugars with water that flows out through the backflow system. If there was a mechanism to help sugar recycling happen, Zhang would find evidence for it in the genes.
Just like with human cells, sugar transporter proteins in grapes are prescribed by different genes whose expression can be detected through RNA sequencing in the lab. Ultimately, Zhang found ten sugar transporters in the pedicel from Syrah and Merlot grapes, which suggests the molecular machinery for the recycling is, indeed, present in the pedicels.
Implications for Irrigation
How and, crucially, when grapevines use and transport water and sugar has been the twin focus of Zhang’s research and that of her advisor, professor Markus Keller, as well. Zhang graduated in July with her doctorate in horticulture, but it isn’t the end of her work at WSU. She began post-doctorate work at WSU-IAREC this summer and continues to build upon years of research that has major implications for irrigation and vineyard management.
“What we need to study next and more specifically is where these sugar transporter proteins are located in the pedicel,” she said. “Then we’ll continue to gain a fuller understanding of the grape’s structure and functions.”
Read about Zhang’s previous work see “Going with the Flow” in an archived Voice of the Vine article by Brian Clark. Learn more about wine science research at WSU at wine.wsu.edu.
Governor, Industry Leaders to Break Ground for Wine Science Center at WSU Tri-Cities
Washington Governor Jay Inslee will join wine and grape industry leaders, economic development and government partners, generous donors, community supporters, and Washington State University officials at 10 a.m. Sept. 26 to break ground for the Wine Science Center at WSU Tri-Cities.
The groundbreaking ceremony will take place at the corner of George Washington Way and University Drive, at the entrance to the WSU Tri-Cities campus in Richland.
Research and teaching conducted at the Wine Science Center will be specifically tailored to the challenges and opportunities faced by grape growers and wine makers in Washington state, and is projected to help triple the economic impact of this $8.6 billion industry to reach more than $20 billion by 2020.
“Having this research facility is critical to the continued growth of our Pacific Northwest wine industry,” said Ted Baseler, President and CEO of Ste. Michelle Wine Estates, WSU Regent, and chair of the WSU Campaign for Wine.
The Wine Science Center Development Authority selected Lydig Construction, Inc. and ALSC Architects of Spokane to design and build the facility. The $23 million building will have approximately 39,300 gross square feet and is being designed to LEED Silver standards.
The conceptual design includes a research and teaching winery, state-of-the-art research laboratories, classrooms, conference rooms, and a regional and international wine library. A dramatic central lobby will provide views of the research winery production floor as well as of the nearby Columbia River and the WSU Tri-Cities campus.
“Research will ensure that we produce the best wine grapes. Research will then help us make great wines with distinct flavors that become sought after internationally,” Baseler said. “This facility and the teaching program at WSU will produce a workforce pipeline of trained WSU graduates – for our vineyards, for our wineries, and for all the allied industries that work with us.”
The Wine Science Center Development Authority is a unique partnership managed by the City of Richland. The land is donated by the Port of Benton. The fundraising and financing is led by Washington State University. FLAD Architects and Meier Engineering serve as the program architects, and Hill International is the project management firm.
For more details, including a video about the value of the Wine Science Center, visit http://wine.wsu.edu/campaign/
-Melissa O’Neil Perdue
Fall Issue of Viticulture and Enology Extension News Now Available
If we have learned anything from this vintage, it is that timing is everything. In this issue of VEEN, we have a few updates on just that: the timing of different practices. After learning about mite research in Washington, read up on how the timing of water influences vine bud break, followed up with an update on the new and improved Irrigation Scheduler Mobile, designed to help you determine the timing of irrigation. We also have a brief update from the Wine Microbiology lab in Pullman, with a discussion on managing Brettanomyces in wine; and of course, timing of additives and temperature play an important role. Download your copy here.