Theanine and EGCG Concentration In Tea

by Amelia
(Makassar, Indonesia)

Hello! I'm Amelia from Hasanuddin University in Indonesia. I'm currently working on a research assignment about "the effects of green tea for a better declarative memory"

Thank you for all your writings in this site, it sure is a big help for me.

But I got a bit problem here, I can't find how many EGCG and theanine are released from the tea after the first brewing, and what about the second brewing.

Would the theanine and EGCG still released? And with the fewer concentration, would it still give the benefit effects on the brain?

And how many times should we brew the same leaves?

Thank you for your help.
Sincerely,
Amelia

Answer:

Amelia, the reason such statistics are not widely available is because they are high dependent on the quality of the tea itself.

The quality of the tea depends on a large number of factors:

- Timing of the crop - first crop in spring will be richer in theanine in EGCG

- How many times the crops are harvested

- The plantation altitude

- Storage conditions

- Tea bags or loose-leaf

- and more!

The following article provides some useful guideline, but it is not clear how the USDA obtains their tea samples.

From experience, I would say at 10% catechins level, we are talking about very high quality loose-leaf - the kind of teas I tend to handle.

EGCG Content USDA Study Reveals Healthiest Green Tea

First infusion will be the most nutritious.

After that, a high quality green tea will still yield some EGCG, but later infusions will have less of theanine and caffeine because they are more soluble.

High quality green tea generally last 3 infusions - even more for higher grades.

Tea is an agricultural product - so trying to pin down a consistent chemistry profile is always going to be tricky.

I hope this helps.

Julian