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What a Plant Knows
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After water, tea is the world’s most popular drink. Now three New York City high school students [Catherine Gamble, Rohan Kirpekar and Grace Young] have discovered what may be a brewing scandal. Because they found stuff in lots of teas that shouldn’t be there.
The students were guided by professional researchers as they worked their way through 70 teas and 60 herbal varieties. The material tested came from 33 companies and originated in 17 countries.
The high schoolers extracted and amplified the tea DNA and then sent it to a sequencing facility. They then compared the sequences they got back with known sequences listed in the GenBank database maintained by the U.S. National Library of Medicine.
The junior scientists found that four percent of the straight teas contained additional plant material. And more than a third of the herbal products included unlisted ingredients – such as the weeds bluegrass and white goosefoot. Four of the herbal mixes contained relatives of parsley. And seven had unlisted chamomile.
The research was published in the Nature journal Scientific Reports. [Mark Stoeckle et al., "Commercial Teas Highlight Plant DNA Barcode Identification Successes and Obstacles"]
The effort shows that it’s possible to cheaply identify food ingredients and do quality control. And all that chamomile may represent an attempt to keep us calm about impurities.
—Cynthia Graber
[The above text is a transcript of this podcast.]
[Scientific American is part of the Nature Publishing Group.]
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9 Comments
Add CommentImpressive work. Thanks to SA for giving the students some well-deserved attention. Hopefully the article will inspire a few more kitchen DNA sequencing kids to fill the gaping hole in food quality information from the FDA.
Reply | Report Abuse | Link to thisThat is impressive work for high school students. They achieved something our own FDA cannot achieve...quality control. Maybe we should replace the FDA with these "very intelligent" high school students and start pointing fingers and naming names of these companies and countries who are polluting our foods and beverages with questionable plant materials and chemicals.
Reply | Report Abuse | Link to thisYou should've told us the name of this New York high school so we can donate to their advanced science class...unless they are afraid these companies would try to buy the school off or harm them in someway to keep them quiet.
It seems to me like those could be common weeds in tea fields. They may not have been intentional additions. The chamomile, perhaps, could be from processing several types of tea on the same equipment. I wouldn't get too up tight over this just yet.
Reply | Report Abuse | Link to thisIt's worth tea & coffee users knowing that the plants have different effects. Tea is more introspective & surreal, while coffee is more speedy; the plant chemicals affect the caffeine molecules differently & alter the way the body processes it... but, in larger doses, after caffeine tolerance has sufficiently built up, caffeine has a depressant effect.
Reply | Report Abuse | Link to thisGetting too uptight is bad in accordance with the word 'too'. Anyway, yes, it could be accidental adulterant, & then again some companies are surely adding filler (the stuff is sold by weight after all).
Reply | Report Abuse | Link to thisAs someone allergic to chamomile who drinks a lot of tea, I'd really like to know which brands had chamomile in them. I seriously disagree with the idea that "all that chamomile may represent [is] an attempt to keep us calm about impurities!"
Reply | Report Abuse | Link to thisI really don't care.
Reply | Report Abuse | Link to thisI refuse to believe my Earl Grey is not as pure as the
driven snow.
It TASTES fine!
I would have loved to have done this kind of research at school! Great work from the students at Trinity School in New York City. We've linked to this at www.genome-engineering.com/checking-up-on-tea.html
Reply | Report Abuse | Link to thisExactly.
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