Caffeine is a naturally occurring substance found in the leaves,
seeds of fruits more than 60 plants. These include coffee and cocoa
beans, kola nuts and tea leaves, which are used to make many
favorite beverages such as coffee, tea and cola drinks, and foods
such as chocolate. Caffeine also is extracted from plants and
manufactured synthetically for use as a flavor in some food
products.
The
caffeine content in coffee bean varies according to the species. Of
the two main species - Robusta and Arabica - the first contains on
average 2.2%, and the second 1.2% of it: in the roasting process, in
spite of a general loss in weight, the caffeine ratio decreases
rather little.
Contrary to what is generally though, the organoleptic
characteristics of bitterness in coffee are only marginally due to
its caffeine content.
The
threshold value over which caffeine intake could cause trouble is 10
milligrams per kilo weight a day
(that is 550 milligrams for the
average woman, and 700 milligrams for the average man).
The
quantity generally recommended, for a positive effect on the
organism is of 3-4 coffees at most: but naturally, the stimulating
effect and its duration vary from person to person. Suffice it to
say that many people don't drink coffee at night for fear of not
being able to sleep, whilst other people drink it precisely to
induce sleep!
Below
are some guideline for caffeine content in beverages:
