For winemakers (and wine drinkers), a keen sense of smell is essential. Without smell, one can taste little. Now researchers have devised what they call an "electronic nose" that they say detects fruit odors more effectively than the human sense of smell and could someday be used in the winemaking industry.
Spanish and Swedish engineers from the Polytechnic University of Valencia in Spain and Sweden's University of Gävle have created an electronic nose with 32 sensors that can distinguish pears from apples, which contain similar chemical compounds called esters. The researchers said the technology could eventually be used to distinguish the quality or type of grape or recognize a wine's vintage.
Their setup bears no resemblance to an actual nose, rather it is a desktop apparatus connected to a computer.
"The fruit samples are placed in a pre-chamber into which an air flow is injected which reaches the tower with the sensors, which are metal oxide semiconductors that detect odorous compounds such as methane or butane," José Pelegrí Sebastiá, co-author of the paper, said in a statement.
Software is then used to gather and analyze the real-time data. The results can then be viewed on a 3D graph to compare their scores.
This study, published in the Sensors and Actuators A journal, is the starting point for further research to develop multisensor systems that will allow the device to differentiate more complex mixtures.
As far as their claim that an electronic nose could do a better job than humans, Daniel Baron, director of winemaking at Silver Oak Cellars, is skeptical. Silver Oak produces only cabernet sauvignon from wineries in Napa and Alexander valleys in California and has gained a cult status, often named in a small list of prestige wineries, including Far Niente, Groth Vineyards & Winery and Opus One.
"The human nose is amazingly sensitive," Baron told TechNewsDaily. "If you were to tell a trained sensory analyst (some of whom can detect 1,500 different types of molecules by smell) that a machine can differentiate between an apple and a pear, he would not be impressed."
Smell is inextricably linked with taste, and Baron relies on both senses to make critical decisions from the time the grapes are ripening on the vines to the final blends created in the cellar. When to pick, when fermentation is complete and when to press are all determined by tasting. The sense of smell is so critical to the process that Baron won't travel during January when Silver Oak begins to determine the blend for that year and will go through upwards of a 100 permutations in deciding the blend of that particular vintage.
"If I get a cold in January, all work stops," he said. "Maybe with a mechanical nose I wouldn't have to worry about it."
However, technology has played a growing role in winemaking , especially in California where the industry has been very open to innovation, Baron said.
For instance, at Silver Oak sorting grape clusters by hand has given way to optical sorters that do the work by identifying color variations, while tanks are turned and pumped using an automated system. Technology at the wineries is used more for detecting defects and automating tedious processes than making critical decisions in the winemaking process, Baron said.
But there's one thing that humans can do that computers can't — at least not yet — and that's smell or taste something for the first time and decide it's delicious.
"The human nose can do that, but I'm not sure how you could program a computer to do it," Baron said.
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