Page 190 - Encyclopedia of Chemical Compounds 3 Vols

CAFFEINE

Interesting Facts

• Americans drank 6.3 caffeinated soft drinks in
billion gallons of coffee, 2003.
2.4 billion gallons of tea,
and 15.3 billion gallons of

that act on the nervous system to produce alertness, excite-
ment, and increased physical and mental activity.

HOW IT IS MADE
Caffeine can be extracted from coffee, tea, and kola
plants by one of three methods. These methods are used
primarily to produce the decaffeinated counterparts of the
products: decaffeinated coffee, decaffeinated tea, or decaffei-
nated soft drinks. A commercial variation of these procedures
is to treat the waste products of tea or coffee processing, such
as the dust and sweepings collected from factories, for the
extraction of caffeine.
In the first of the three extraction methods, the natural
product (coffee beans, tea leaves, or kola beans) are treated
with an organic solvent that dissolves the caffeine from the
plant material. The solvent is then evaporated leaving behind
the pure caffeine. A second method follows essentially the
same procedure, except that hot water is used as the solvent
for the caffeine. A more recent procedure involves the use of
supercritical carbon dioxide for the extraction process.
Supercritical carbon dioxide is a form of the familiar gas
that exists at high temperature and high pressure. It behaves
as both a liquid and a gas. Not only is the supercritical carbon
dioxide procedure an efficient method of extracting caffeine,
but it has virtually none of the harmful environmental and
health problems associated with each of the other two meth-
ods of extraction.
Caffeine is also made synthetically by heating a combi-
nation of the silver salt of theobromine (C 7 H 8 N 4 O 2 Ag) with
methyl iodide (CH 2 I), resulting in the addition of one carbon

CHEMICAL COMPOUNDS 139