Coffee is one of the most widely consumed beverages in the world. It is prepared from the roasted seeds– commonly referred to as beans – of the coffee plant, and is usually served hot but can also be served cold.

 

Caffeine is one of the 1500 constituents of coffee that gives coffee its distinctive character. It occurs naturally in coffee beans as well as in tea and cocoa. Caffeine also acts as a mild stimulant, increasing mental alertness and speeding up the thought process.  It is because of this that some people prefer to drink decaffeinated coffee, particularly in the evening, when they might wish to relax and sleep rather than be alert.

A typical 5 fluid ounce (ca. 150 ml) cup of coffee contains 80- 90 milligrams of caffeine, depending on the method of preparation. Coffee represents 71% of all the United States caffeine consumption, followed by soft drinks and tea.

 

Following is comparison between caffeine in coffee and other drinks:

mg caffeine/serving
Coffee (per 150 ml cup) - from roast and ground		~80
Coffee (per 150 ml cup) - from instant		~60
Decaffeinated Coffee (per 150 ml cup) (either roast, ground or instant)		~3
Tea (per 150 ml cup)		~40
Cola (per 330 ml can)		~30
Plain Chocolate (50g)		~20