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Unlisted ingredients in teas and herbal brews revealed in DNA tests by high school students
Rockefeller University ^ | July 21, 2011 | Unknown

Posted on 07/21/2011 7:40:12 AM PDT by decimon

Take a second look at your iced or steaming tea. Guided by scientific experts, three New York City high school students using tabletop DNA technologies found several herbal brews and a few brands of tea contain ingredients unlisted on the manufacturers' package.

The teen sleuths also demonstrated new-to-science genetic variation between broad-leaf teas from exported from India versus small-leaf teas exported from China.

Guided by DNA "barcoding" experts at The Rockefeller University, an ethno-botanist at Tufts University and a molecular botany expert at The New York Botanical Garden, co-authors Catherine Gamble, 18, Rohan Kirpekar, 18, and Grace Young, 15, of Trinity School in Manhattan, published their findings today in the Nature journal Scientific Reports.

The unlisted ingredients included weeds such as annual bluegrass and herbal plants such as chamomile. The surprise ingredients are mostly harmless but could affect a tiny minority of consumers with acute allergies. Three (4 percent) of the 70 tea products tested and 21 (35 percent) of 60 herbal products had unlisted ingredients.

For example, DNA testing showed that an herbal infusion labelled "St. John's wort" (Hypericum perforatum) included material from a fern in genus Terpischore. A DNA "barcode" obtained from another herbal tea labelled "ginger root, linden, lemon peel, blackberry leaves, and lemongrass" matched annual bluegrass (Poa annua), a common weed unrelated to lemongrass. Four herbal infusions yielded sequences identical or nearly identical to the tea plant, C. sinensis but none listed "tea" as an ingredient. The most common non-label ingredient, found in seven herbal products, was chamomile (Matricaria recutita).

Four products yielded barcodes of plants closely matching parsley, but none listed ingredients in that plant family.

Other unlisted ingredients included the common weeds white goosefoot (Chenopodium album) and red bartsia (Odontites vernus); a garden flower, lantana (Lantana spp.); an ornamental tree, Taiwanese cheesewood (Pittosporum pentandrum); and herbal plants such as alfalfa (Medicago sativa), lemon balm (Melissa officinalis), heal-all (Prunella vulgaris), blackberry (Rubus spp.) and papaya (Carica papaya).

"After water, tea and its many herbal variations represent the world's most popular beverage – by far. Literally billions of cups are consumed every day, more than all the coffee, pop and every other drink combined," says Gamble, who begins studies at Harvard in September. "What's in those little bags of tea and herbal tea products is a matter of interest to billions of people."

"It's important to list every ingredient in a product because some people need to be very careful about what they consume," says Kirpekar, who enters Columbia in the fall. "Allergy symptoms might be just watery eyes but some people can get more seriously sick and they'd never know the reason was in their comforting hot drink. We were surprised to find many herbal teas in particular with unlisted ingredients."

"It's a mystery why ingredients are unlisted," adds Young, who can make the rare boast at 15 of having co-authored a peer-reviewed academic paper. "It might just be a weed picked up during harvesting or the residue of a plant used in one product gets passed to the next product in a processing facility."

"Maybe unlisted ingredients like chamomile or parsley are added to provide flavour or color to herbal teas, serving the same purpose as garlic or onion in cooking. Perhaps manufacturers want to sell full looking bags and pad them with filler."

"All of that, though, is speculation; proper answers require a completely different type of investigation."

DNA barcoding technology identifies and distinguishes known and unknown species quickly, cheaply, easily and accurately based on a snippet of genetic code. Experts at various institutions around the world are building an authoritative library of DNA barcodes for both plants and animals.

Teas are made from leaves of the tea plant, Camellia sinensis; herbal infusions, which are often called "teas," use the roots, leaves, stems, seeds, or flowers of many different plants. But appearance does not easily identify the bits of dried plants, which sometimes are also cooked or fermented, that are used to prepare infusions and teas. The researchers found the plant DNA extremely resilient and obtained barcodes from 90 percent of the 146 products sampled

The products, half teas and half herbals, from 33 different manufacturers spanning 17 countries, were collected or purchased at 25 locations in New York City including stores, school dining halls, and the homes of the investigators.

Some of the DNA extractions and amplifications were carried out on a dining room table in the apartment of mentor and barcoding expert Mark Stoeckle, an adjunct faculty member with the Program for the Human Environment at The Rockefeller University.

The lab equipment was purchased used on the Internet for about $5,000, highlighting the viability of public DNA-based plant identification. After extracting and amplifying the DNA in the home lab, the samples were mailed to a commercial DNA sequencing facility. The total cost was about $15 per sample and took about 24 hours in total.

Most of the DNA analysis was done at The New York Botanical Garden. When the students obtained a DNA sequence, they checked it using the GenBank DNA database maintained by the US National Library of Medicine, that retrieves matching sequences and candidate species names almost instantly.

"These results demonstrate a low-cost approach for plant identification that could be used in educational, regulatory, and research settings to produce practical information and scientific insight," says Stoeckle.

Also mentoring the students were Jesse Ausubel, director of the Program for the Human Environment at Rockefeller University and vice-president of the Alfred P. Sloan Foundation; Damon Little of the Lewis B. and Dorothy Cullman Program for Molecular Systematics, The New York Botanical Garden; and Selena Ahmed of Tufts University. One of the world's top experts on teas, Ahmed co-authored the 2011 book Tea Horse Road about tea production, trade, and ancient tea rituals in southwestern China where tea drinking probably originated.

In addition to the unlisted ingredients, the young scientists helped discover that the tea plant includes a genetic difference between broad-leaf assamica variety tea exported from India and small-leaf sinensis variety tea exported from China, the two largest tea-producing countries by far.

"We were excited to make a genetic discovery, particularly in an important crop plant like tea that scientists have scrutinized in detail," says Young.

"This finding will help track commercial shipments and aid research on the geographic origin and diversity of wild and cultivated tea plant resources," says Ahmed.

Says Little: "After tea ingredients are dried and processed into powders it is very difficult to determine which species the ingredients came from. This study demonstrates the power of DNA barcoding to easily and rapidly identify plant materials. I hope that manufacturers will adopt this technology for quality assurance."

The students also helped construct a "Klee diagram," a clever new way to visually represent the genetic relationship between species. Like a heat map, where hot is shown in red and cold in blue, their Klee diagram depicts the genetic relationships among and within the families of plants consumed as teas, using a color scale from red (a close genetic relationship) to blue (distant). Based on the DNA of 39 plants tested, the image is the world's first family portrait of tea and herbal tea plants.

"The Klee diagram creates a genetic 'mood chart' for mint, ginger, linden and other herb teas," says Jesse Ausubel, director of the PHE at Rockefeller University. "The students grouped 39 plants used for herbal tea into six genetic blocks: one anchored by ginseng and parsley, another by Echinacea and the asters, a third large mint block encompassing also jasmine and lavender, a fourth fruity block with hibiscus and orange, a fifth block with rooibos and other beans, and a final block with lemongrass and other grassy plants."


TOPICS: Food; Health/Medicine; Science
KEYWORDS: barcodes; dna; dnabarcodes; evolution; tea
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To: The Sons of Liberty

Fresh Appalachian Mountian air. And you?


21 posted on 07/21/2011 8:54:53 AM PDT by MHGinTN (Some, believing they can't be deceived, it's nigh impossible to convince them when they're deceived.)
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To: The Sons of Liberty

Fresh Appalachian Mountain air. And you?


22 posted on 07/21/2011 8:55:16 AM PDT by MHGinTN (Some, believing they can't be deceived, it's nigh impossible to convince them when they're deceived.)
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To: bgill
I’ve yet to see rat droppings or bugs listed as ingredients in packaged foods but we all know it’s in there.

There are FDA-allowable standards for miscellaneous ingredients (filth) in cased meats. George Carlin called them "rodent hairs, roach droppings, bug parts".

23 posted on 07/21/2011 9:22:44 AM PDT by Bloody Sam Roberts (If you think it's time to bury your weapons.....it's time to dig them up.)
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To: MHGinTN; momtothree

I put my used tea bags on my indoor plants and my roses...

I also put my coffee grounds on my roses...

they love them too

:)

When I went to NZ in 2009 I brought back a pound package of loose Choysa tea...

My Mums favorite...

No extra plantlife...

My daughter says it tastes like Earl Grey..


24 posted on 07/21/2011 10:08:37 AM PDT by Tennessee Nana
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To: jimpick

PING to #24


25 posted on 07/21/2011 10:11:17 AM PDT by Tennessee Nana
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To: MHGinTN

Smog and exhaust fumes - NOT by choice.


26 posted on 07/21/2011 12:36:29 PM PDT by The Sons of Liberty (Psalm 109:8 Let his days be few and let another take his office. - Mene, Mene, Tekel, Upharsin)
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To: MHGinTN

I like Twining’s Earl Grey, but will try Bigelow this winter. I tend not to drink much tea in the summer, just water (yes, I’m a yankee).


27 posted on 07/21/2011 12:42:31 PM PDT by Betis70 (Bruins!)
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To: momtothree

I hope you don’t think I was making fun of you. I love tea too.


28 posted on 07/21/2011 7:28:02 PM PDT by DManA
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To: DManA

“I hope you don’t think I was making fun of you...”

Not at all! You have always been fun and I adore “joshin” around. I’m not a “sensitive” type!


29 posted on 07/22/2011 7:58:02 AM PDT by momtothree
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To: Reeses
These young people are well on their way to becoming Democrat-voting government paid nazis with little to do but harass the productive sectors of the economy. Nazis find harassing tobacco people boring now so have moved on to food, another harmfully addictive substance.

Yeah, because what possible reason would we have to question the ingredients of foodstuffs imported from China?

30 posted on 07/22/2011 8:36:02 AM PDT by ReignOfError
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To: ReignOfError
We shouldn't be importing food from China. If it's that much cheaper, despite traveling 8,000 miles, put an import tax on it and use the money for building autonomous robot farm workers that understand English.

If these nazis in training analyzed the DNA in corn flakes from Ohio, many people would never eat them again. You don't want to know. The tyranny of lab instruments that can measure parts per trillion is upon us. It's what enabled the whole global warming scam.

31 posted on 07/22/2011 9:13:09 AM PDT by Reeses (Obamacare: do not resuscitate)
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To: Reeses
We shouldn't be importing food from China.

That leaves India, Kenya or Sri Lanka. Tea doesn't grow well here.

If these nazis in training analyzed the DNA in corn flakes from Ohio, many people would never eat them again. You don't want to know.

YOU don't want to know. Don't project that onto others. Are there insect and rodent parts, dirt and feces in there in some measurable amount? Sure. Food is made from living things, and life isn't antiseptic. But if the corn flake maker is fluffing them out with sawdust because it's cheaper than corn meal, I sure as hell do want to know. My food allergies are fairly mild, but for a lot of folks that information is pretty damned important.

But hey, go ahead and protect your own ignorance and label scientists who challenge it "Nazis," if that's what gets you through the night.

32 posted on 07/22/2011 10:01:32 AM PDT by ReignOfError
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To: decimon; mickie
The Food Nazis will seize upon this report as God's Truth and will use it as yet another attack on what's in our wretched, abominable, unhealthy daily menu of food and drink.

It won't be long now that we'll only be allowed to eat and imbibe what's on Moochelle Obama's approved list of edibles......all organic stuff, of course, and only those leafy or rooty things such as are grown in her own well-toned White House garden.

All foods that are on the federally-proscribed list will be required to have a black skull-and-crossbones image printed on the packaging.

Leni

33 posted on 07/22/2011 10:18:07 AM PDT by MinuteGal (We need ObamaCare Like Nancy Pelosi Needs a Halloween Mask)
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