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Taiwan uses science to prove oolong tea’s original source

If you are a serious tea drinker like me, what is the information you would be looking for first in your purchase decision on a certain type of tea, say loose oolong tea? Is it price, brand, taste, country of origin, or the nitty-gritty tea district and tea plantation where it was produced? Ah, little doubt that price often is our first screener. But among all these decision points, if you can track the tea’s original source down to the tea plantation, you would be in a better position to judge its true value. 

Unfortunately, that most crucial information is often unavailable to end consumers, making tea shopping a constant guessing game that leads to a hit-or-miss experience. Even in Taiwan where unflavored and unblended oolong teas remain the mainstream in the traditional loose tea market, consumers are increasingly concerned about another type of alteration: mixing oolong tea leaves (of different grades) from different tea plantations or districts at home and abroad. Because they are worried that they would pay for something that is not worth the claim.

Up until recently, only the very seasoned tea masters and connoisseurs could truly “taste” where an oolong tea came from because their trained taste buds could discern the subtle difference in tastes affected by each tea district’s distinct climate, minerals in the soil, and tea cavaliers. In other words, the process of proving an oolong’s original source has been more of an art than a science. 

So it is encouraging for consumers (and retail tea vendors who are also vexed by this issue) when I learned the other day from Taiwanese media that researchers in Taiwan have successfully used a scientific method to prove the original source of the sample oolong tea leaves. 

According to Chien-Chen Lai, the project lead and professor from the researcher Taiwan’s Institute of Molecular Biology, National Chung Hsing University, the environment where a tea tree grows and how tea leaves are processed would affect the reaction of the proteins contained in the leaves. So they applied the “proteomic techniques, nanoscale liquid chromatography/tandem mass spectroscopy (nano-LC/MS/MS), and 2-layer feature selection mechanism” and discovered 20 proteins that can be used to identify the tea’s original source. The testing of the sample leaves from 23 tea districts in Taiwan, Vietnam, Indonesia, and other countries resulted in a 95.5% accuracy. Lai, currently in charge of the operation of the university’s Proteomic Core Lab, said the team spent two years in developing the web-based OTPS system that can certify oolong tea’s original source by the featured proteins. With the system in place, he hopes that it can help Taiwanese tea farmers to build up their product traceability and uphold Taiwan oolong tea’s reputation in the tea market.

[If you're interested in the detail of the team's work, you can find their report in the journal Food Chemistry.

Although a layman in bio-tech and food science, I would assume what this science method has achieved is similar to the ancestry composition shown in PBS's program Finding Your Roots. In this program, the guests went through a cutting-edge DNA analysis and were presented a chart showing their ancestry composition, sometimes as specific as a certain tribe in Africa, for example. In the similar vein, I supposed the proteomic techniques would help us unmask the tea district composition of the tested tea leaves. If the major tea production countries can adopt the similar technology to tackle the issue of fake teas, it would benefit tea consumers and tea vendors who value pure tea. 

Cecilia Fino-Chen
Cecilia Fino-Chen


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