White Tea Study Reveal Inconsistencies?

by Matt
(Mantova, Italy)

I want to show this 2001 white tea study entitled "Potent antimutagenic activity of white tea in comparison with green tea in the Salmonella assay"


The full text version

http://www.pubmedcentral.nih.gov/articlerender.fcgi
?tool=pubmed&pubmedid=11448643

First issue: cut leaves and bud are better than uncut leaves and bud?

In the final discussion:

"When white tea was cut to a consistency found in commercially available tea bags, this increased the antimutagenic activity, and HPLC experiments revealed improved overall extraction of the major UV absorbing constituents (not shown). "

Second issue: leaves are better than buds?

In the 3.3 paragraph:

"Finally, because Exotica tea is a ‘cut’ version of a loose leaf variety (Mutant white), we obtained the uncut tea and carefully separated the leaves and buds.

The antimutagenic activity of cut leaf tea was greater than that of cut buds alone, or the mixture of cut leaves and buds (Fig. 7c).

The uncut tea was significantly less effective than the cut variety against IQ (compare the final two bars in Fig. 7c).

Testing of cut and uncut Premium green tea showed only slightly higher antimutagenic activity of the former (data not shown)."

Third issue: white tea processing

After having read your white tea articles I have noticed the erroneous description reported by study authors inherent white tea processing

This is their description

"White tea, which has received little if any attention for its health benefits, represents the least processed of teas in that it goes through steaming and drying without a prior withering stage."

Also you can see fig 1 http://www.pubmedcentral.nih.gov/articlerender.fcgi
?artid=2266698&rendertype=figure&id=F1

Thank you very much for your reply

Matt

Answer:

Thank you for pointing me to the article and I have to say it is a very interesting read.

I venture a few thoughts below, please feel free to disagree.

Issue 1&2:

I don't actually quite understand why the scientists are separating out the leaves and buds.

The difference between high and low grade white tea is not just about buds and leaves.

Although higher grade white tea tends to have more buds than leaves, this is usually a sign of age and timing i.e. first harvests in the season usually yields the highest grade tea, which happens to have more buds than later harvests.

Lower grade white tea such as those used to make teabags is made more of leaves. These are matured leaves, not the tippy leaves associated with higher grade white tea.

The leaves, after they have opened up, can be further classified into slightly unfurled, 1/3 full size, 1/2 full size etc.

It is interesting to note that cut leaves are more potent than the mixture of buds/leaves of similar timing, but to conclude than matured leaves will be more potent than tippy leaves - I can't see the point (unless I am missing something, which is possible).

Buds are not always better than buds. It depends on a lot of factors. For example, Dragon Well green tea is always harvested one-bud-two-leaves or one-bud-one-leaf, and never single buds. I think this study confirms this.

Issue 3:

Such view is very common. They fail to see that traditional white tea is never steamed or heated at high temperature.

The secret lies in the withering - control of temperature, airflows and moisture to allow natural maturation.

It also surprises me that the scientists say white tea chemical composition is "little known", when it is already part of standard Chinese university studies.

If the scientists involved could learn the Chinese language and spend a couple of days reviewing their findings, I think they will save much years and dollars.

On the other hand, I am glad that they concluded that "complete" tea containing the full nutritions are more potent than "artificial" tea containing only the major compounds.

The finding is consistency with other studies I have come across that tea compounds often act in synergy - a fact often ignored by tea supplements marketers.

Those tiny tea compounds that we have not yet understood play a very important part!

I hope this help. And thanks for pointing me to this interesting article.

It is nice to speak to a fellow tea lover!

Comments for White Tea Study Reveal Inconsistencies?

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Apr 07, 2008
cutting
by: Matt

I thank you for your exhaustive answer.

When I have read this statement:

"When white tea was cut to a consistency found in commercially available tea bags, this increased the antimutagenic activity, and HPLC experiments revealed improved overall extraction of the major UV absorbing constituents (not shown)"

I have thought that if we cut/chop a high grade loose tea (white or green) just before we brew it, we improve overall extraction of tea compounds (catechins, caffeine, and perhaps teanine, quercetin, myricetin) and so antimutagenic activity increase (maybe also other activities increase)

Do you agree with me on this construction?

Another issue: findings of researchers, in this study, about white tea chemical composition coincide with findings of chinese researchers?

"When green tea was separated using the same HPLC conditions (not shown), there were higher levels of CAT and EC, but lower concentrations GA, TB, ECG, and caffeine compared with white tea (Table 1). Interestingly, EGCG was present at equally high levels in both teas."


I agree with you when you state

"The finding is consistency with other studies I have come across that tea compounds often act in synergy - a fact often ignored by tea supplements marketers.

Those tiny tea compounds that we have not yet understood play a very important part!"

Thanks in advance










Apr 08, 2008
Further Discussion
by: Julian

Matt

To quote the paper:

"When white tea was cut to a consistency found in commercially available tea bags, this increased the antimutagenic activity, and HPLC experiments revealed improved overall extraction of the major UV absorbing constituents (not shown)"

Without reading the entire article, this paragraph seems to imply teabags are more antimutagenic than loose tea.

There is no evidence from this study that this is the case (see my previous answer).

I whole heartedly agree your other interpretation is possible.

It is just that as a loose tea drinker, I struggle to understand why someone would want to cut and chop say, their one-bud-two-leaf (a White Peony?) to enhance its antimutagenic properties by increasing the extraction rate.

White peony is meant to be infused multiple times, so the lower extraction is exactly what is needed to make it lasts longer.

Not that extraction rate is the same as the level of soluble solids.

Tea contains key compounds EGCG, theanine and caffeine and they dissolve in water at different rate.

My suspician is that once you cut and chop, you lose too much caffeine and theanine at the first infusion, and reduces the overall enjoyment and quality of your beverage.

White Tea and Chinese Research

I have no idea if the Chinese scientists are doing this study.

The problem with this study is that the conclusion is almost meaningless because of the sheer varieties of green tea and white tea that exist in China, and worldwide.

Tea composition can vary significantly by species, type of leaves picked, harvesting season and processing.

(Reason why some tea plantations rotate crops by season.)

A meaningful way to compare green tea and white tea would be to take the same tea plants harvested in the same time, same place, process them different way (thus you get your green and white), then test them.

What do you think?

Apr 09, 2008
Further discussion
by: Matt

Dear Julian,

I thank you for your last answer.

I agree with you, it is difficult to understand why, in this study, teabags are better than loose tea; it is possible that, despite lower quality of teabags, their higher extraction rate improves antimutagenic activity of buds and leaves.

I agree with you when you state

"White peony is meant to be infused multiple times, so the lower extraction is exactly what is needed to make it lasts longer"

"My suspician is that once you cut and chop, you lose too much caffeine and theanine at the first infusion, and reduces the overall enjoyment and quality of your beverage"


Do you know if any chinese studies about the chemical composition (catechins, caffeine) of these teas have been carryed out?

- Pai mu tan (White Peony)
- Huang Shan Mao Feng (Hairy Mountain)
- Tai Ping Hou Kui Tea (Monkey Chief Tea)
- Dong Ting Bi Luo Chun (Green Snail Spring)
- White Monkey
- Pu erh green bingcha
- Pu erh white bingcha

(I have read your article about West Lake Dragon well and and the study conducted by the UK Institute of Food Research. Had researchers studied also these varieties of tea?)

Tanks in advance for your patience

Apr 09, 2008
White tea chemical composition
by: Julian

Matt

Thanks again for your reply.

My research on Chinese studies is sporadic, and to confess, I still haven't found a way to systematically capture their research findings.

The more interesting ones I have come across are documented in the site, such as

White Tea Caffeine Versus Theanine
http://www.amazing-green-tea.com/white-tea-caffeine.html

Chemical Composition By Leaf Age
http://www.amazing-green-tea.com/tender-tea-shoots.html

These studies reflect the general belief of Chinese academic, so I am comfortable with them.

Hope this helps.

Apr 13, 2008
green and white pu erh tea
by: Matt

Thank you again Julian,

another question: have you any informations about green pu erh tea chemical composition (catechins, caffeine), or about white pu erh tea chemical composition?

What are the differeces concerning health benefits between green tea and green pu erh tea? (and between white tea and white pu erh tea)

Thanks in advance

Apr 14, 2008
Green And White Pu-erh Tea
by: Julian

Matt, this is a brand new question and I have moved my answer to a separate thread under the FAQ Forum.

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