 Questions concerning Tea and its benefits
On Jun 4, 8:07 am, psyfl...m wrote:
> Usually these numbers are gathered from the analysis of fresh green
> leaves.
> However, if you´re planning to sell and ship those leaves you´re at
> least supposed to kill the enzymes, in order to block any kind of
> reaction with the polyphenols. That means you have to give them some
> heat treatment, steaming, hot air, panning or whatever, which might
> result in a slightly different picture, but a high content of EGCG in
> fresh leaves would be a good point to start.
> PS: I really enjoy this kind of tea-tech-talk :)
>
> Karsten [still dreaming of a pocket-chromatograph]
>
> On Jun 4, 11:07 am, Nigel <n...@teacraft.com> wrote:
>
> > On Jun 4, 8:08 am, Desirea <steeping...@> wrote:
>
> > > On Jun 3, 1:21 am, tea.exp...@m wrote:
>
> > > > Does anyone know a good source for green tea containing high amounts
> > > > of EGCG?
>
> > > I thought all green teas had the same level of EGCG.
>
> > Indeed they do not!
>
> > The five types of catechins in tea (gallated flavonols and non
> > gallated flavanols collectively) occur at different levels and in
> > different ratios depending on genetic background and growing
> > environment. Levels of EGCG (epigallocatechin gallate) can be higher
> > or lower than some of the other catechins. Typical levels in African
> > teas (assamica) are much higher than in China type teas (sinensis)
> > when the Africans are manufactured the green tea way. For example
> > (see "Diversification of the Tea Product through Value Adding and
> > Business Viability - H.E Nyirenda et al, TRFCA News 2006 p20) cultivar
> > PC190 had EGCG of 329.3 mmol/g while cultivar PC160 had only 165.9 -
> > 24 other cultivars fell between these limits. You can perhaps have too
> > much of a good thing though and PC190 while having the highest level
> > of flavonols was rejected for release to growers as it produced poor
> > quality tea. Nevertheless several of my clients are pursuing
> > intrinsically high EGCG as a marketing USP, along with naturally high
> > L-theanine levels - these are staggeringly high in Malawi clones -
> > PC108 has 3.1 % theanine compared with Japanese culivars at 1.5% under
> > sun - and the Japanese teas are recognised for their theanine content
> > which by shading can still only reach two thirds of the Malawi level!
>
> > Nigel at Teacraft
Thank you all for your tremendous input. I know that when processing
tea's most of the times when they go through what is called a roto-
machine it slices the leaves for further processong of tea bags. This
actually damages the cell wall and allows for quicker oxidation.
Traditionally steaming( more a japanese method) and pan frying ( more
a chinese method) are safer in that they delicately roll the leaves so
as to protect them from damage. I did not know however that the
assamica plant contained more EGCG thats its cousin the sinensis
plant. I was under the impression that the Assamica plant came after
the Sinensis plant when the british invaded India as a result of
china cutting off its trade market back in the 1700's. | 
