Ball 2. Electronic "Tongue" Has a Taste for Tea

This story struck me as a sure bet--science, economics, quirky niche behavior--which is why it's a good thing I don't wager on sports, I guess. Even the British press wouldn't bite on it (as far as I can tell; none of them ever replied to my queries, a lack of professional courtesy that's a real pet peeve of mine). I found it while digging through the abstracts of the upcoming 2010 World Congress on
Biosensors, in Glasgow, UK. This meeting is a great venue for fascinating but largely unproven research.


Attendees at the World Tea Expo in Las Vegas this June will be able to immerse themselves in sessions covering everything from how to open a tea house to the latest in trends and blends.

What they won’t see, however, is a new bit of electronics that potentially could revolutionize their $10 billion industry: an electronic "tongue" that, its inventors say, can quickly and cheaply identify levels of two key taste compounds in tea leaves. Such a test would give both buyers and tasters a rapid means of determining product quality, which for now remains more art than science.

The hand-held device, developed by researchers in Taiwan, assesses levels of molecules known to produce astringency—the tannins that cause the pucker-up quality in many forms of tea—and umami, a general savoriness.

Samples of infused tea are put into the detector, which uses ultraviolet light to excite the leaves and measures the energy they generate in response. Leaves with different quantities of tannins and amino acids linked to umami, particularly one called teanine, produce different amounts
of energy, giving them unique signatures that can be easily identified.

The technique works best with partially fermented teas, such as oolong, a staple of Chinese restaurants around the world. Green tea, too, may also be a candidate, according to the researchers.

Tzong-Jih "George" Cheng, an associate professor at National Taiwan University who helped create the detector, said the technology could appeal to both tea wholesalers, who lack a fast way of gauging quality in bulk, and consumers, who are at the mercy of vendors when it comes to looking for top-shelf product.

Indeed, the Taiwanese researchers tested samples of infused teas of varying prices. They found that cost and quality—at least, according to the electronic tongue's definition—did not reliably agree. "We see that the retail price is not correlated with taste quality in partially fermented teas," Cheng said. "Price cheating is the usual conditions for general consumers."

The cost of the device is roughly $50US, with each test running about
25 cents.