Coffee (Caffeine) : Chemical Constituents and Uses

Morphology and Distribution of Coffee:

Coffee is the dried ripe seed of Coffea arabica or Coffea liberica without the seed coat belonging to the family Rubiaceae. It is also known as coffee bean or coffee seed. Coffee is grown in Ethiopia, Brazil, India, Vietnam, Mexico, Guatemala, Indonesia and Sri Lanka. Coffee is popular in different parts of the world and in the middle east countries, it is known as ‘qahuah’. It is a strong decoction of the coffee seed powder and has its origin in Turkish and Arabic languages. Brazil and India are suppliers of coffee. In India coffee plantations are present in Karnataka, Kerala, Tamil Nadu and Maharashtra.

English: Coffea arabica (fruit). Location: Maui, Kula (Photo credit: Wikipedia)

Coffee plant is an evergreen shrub and bears drupe type of fruits. The fruits are dried and seeds are separated by wetting them and mechanically separating them. After they are dried in heaps which causes fermentation. The seeds which are separated are green in colour. They are roasted until they acquire dark brown colour and possess agreeable odour and bitter taste.

Chemical constituents of Coffee:

The main constituents of coffee bean are caffeine, tannin, fixed oil and proteins. Chlorogenic or caffeotannic acid and sugars like dextrin, glucose etc are also present. Caffeine is present as a salt of chlorogenic acid in the seeds. The smell of the coffee is due to the oil called caffeol which contains furfural, phenol, pyridine and valerianic acid.

Extraction of caffeine :

Caffeine is prepared synthetically from urea or uric acid or extracted from natural sources like coffee bean. Coffee roasters are used in which caffeine sublimed during roasting is recovered for extraction. It is the commercial method.

English: Coffea arabica, Rubiaceae, Arabica Coffee, Mountain Coffee, roasted beans. The unroasted dried beans are used in homeopathy as remedy: Coffea (Coff.) Deutsch: Coffea arabica, Rubiaceae,(Photo credit: Wikipedia)

Uses of Coffee:

• Source of caffeine
• Stimulant
• Diuretic
• Combats toxic effects of CNS depressant drugs.