[geeks] caffeine - differences based on source

[Sandwich Maker]

" From: nate at portents.com
" 
" > strictly speaking, tea contains little or no caffeine at all.
" 
" That doesn't agree with my understanding or experience with teas.  I think
" wikipedia probably has it right:
" 
" "Tea is another common source of caffeine. Although tea contains more
" caffeine than coffee, a typical serving contains much less, as tea is
" normally brewed much weaker. Besides strength of the brew, growing
" conditions, processing techniques and other variables also affect caffeine
" content. Certain types of tea may contain somewhat more caffeine than
" other teas. Tea contains small amounts of theobromine and slightly higher
" levels of theophylline than coffee. Preparation and many other factors
" have a significant impact on tea, and color is a very poor indicator of
" caffeine content.[19] Teas like the pale Japanese green tea gyokuro, for
" example, contain far more caffeine than much darker teas like lapsang
" souchong, which has very little."
" 
" And if for some reason you don't trust the wikipedia article on caffeine,
" I'd refer you to page 438 of "Remington: The Science and Practice of
" Pharmacy" by David B. Troy, University of the Sciences in Philadelphia,
" Joseph Price Remington, Paul Beringer, published by Lippincott Williams &
" Wilkins, 2005:
" 
" "A significant quantity of caffeine is present in tea and coffee and is
" responsible for their CNS stimulatory and diuretic effects."

hmmm...  both are rather newer than my information.  i'll take it that
you're correct.

" > it has theophylline, a structurally similar compound with similar but
" > slightly different effects, less on the cardiovascular system but more
" > on the cardiopulmonary.  remember the folk wisdom about drinking tea
" > when you have a cold?  theophylline has been prescribed as a mild
" > bronchodilator.
" >
" > on most food chemical tests, theophylline will read as caffeine.  this
" > also goes for theobromine in cocoa, structurally similar as well.
" 
" Are you sure that theophylline "reads" as caffeine?  (Maybe it just forms
" an insoluble complex with it?)

they're nearly identical, the same basic structure with just 1
difference, a methyl group in caffeine instead of just a hydrogen in
theophylline.  see http://en.wikipedia.org/wiki/Caffeine#Metabolism
a test that distinguished between these alkaloids would have to be
more difficult than a test that merely detected them.
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