Coffee Back to Map Page Ethiopia Coffee is one of the most important commodities on the international market, second only to oil. In the United States alone, Americans drink about 350 million cups of coffee daily. Although coffee was grown in Arabia as long ago as 675 A.D., coffee                   Ripening coffee fruits cultivation was rare until the fifteenth and sixteenth centuries. The earliest records of coffee use come from Ethiopia, where the fruits were collected, roasted, mixed with other items, and taken on long hunts as a staple. The leaves were chewed to leach out chemicals that curbed hunger and fatigue. Coffee is believed to have first been brewed as a beverage by the Arabs, spreading to Egypt by the early 1500s, to Italy by 1616, and to England by 1650, where over 3,000  coffee housessprang up in less than 25 years. Coffee houses quickly became the centers of artistic, political,and other intellectual venues. At first, the Arabs dominated coffee production and export, taking great measures to protect their industry by boiling the seeds to kill the embryo and prevent germination after sale. Not until the Dutch smuggled live seeds and started plantations in the East Indies was the Arabian monopoly broken. Eventually, plantations spread to the West Indies, Suriname, Brazil, and other tropical and subtropical regions. Today, Brazil and Colombia are the world's leading coffee producers. Coffee arabica accounts for about 90% of the world's coffee production. Coffea is a genus in the Rubiaceae family, one of the largest angiosperm families, with 650 genera and 13,000 species. (Cinchona is another economically important genus in Rubiaceae. The bark of Cinchona offers quinine, the alkaloid used to treat malaria [see "Using Bark to Cure the Bite" ].   The remaining 10% of the world's coffee comes from C. canephora (9%) and C.
Flower Cluster   liberica (1%);  these types are known as robusta coffee and Liberian coffee, respectively. C. canephora has a less appealing taste than C. arabica and is generally used to make instant and/or decaffeinated coffee, in which the flavor can be easily masked. C. liberica is very bitter and serves as a filler when blending coffees. Both C. canephora and C. liberica are generally grown in Africa and Asia, and they do well at lower elevations than C. arabica . C. arabica requires about 60-100 inches of rainfall per year and  4,000-6,000 feet elevation. White flowers produced in clusters in the leaf axils take 7-9 months to mature after fertilization. During maturation, the fruits turn from green to a deep red. The plants produce their first crop after the age of 3 years and continue producing for 3 5-40 years, yielding 5-6 pounds of fruit per year. The fruits, commonlyknown as beans, are harvested by hand. Hand harve sting is necessary because the fruits ripen at different times on the same plant and the trees tend to grow on  steep mountains and hills. When harvested, the fruits are depulped.  The seeds undergo enzymatic fermentation (not to be confused  with alcholic  fermentation) before being washed, dried, and roasted. The   different aromas and flavors of  coffee are o btained by varying the temperature and time of roasting. Coffee processing Coffee contains many chemicals that have been isolated and studied, including trigonelline, chlorogenic acid, phenolic acids, amines, and mercaptans. But coffee's principal physiological effects are due to the alkaloid caffeine. Alkaloids are a major class of natural products that have a physiological effect in other organisms.  They characteristically contain carbon, hydrogen, nitrogen, and in many cases, oxygen.
Because of their potent pharmacological effects, alkaloids are the basis for many drugs. Caffeine increases heartbeat, blood pressure, and respiration. It has been shown to alleviate hunger, drowsiness, and fatigue; to promote the use of fat reserves for energy; and to act as a vasoconstrictor, helping relieve the pain of headaches caused by vasodilation.   However, caffeine consumption also has a down side, with various amounts causing insomnia, nervousness, and irritability in some individuals. Depending on the method of processing, a 5-ounce cup of coffee has about 130 mg of caffeine, compared to instant coffee with about 50 mg and decaffeinated coffee with 2 mg. Caffine Molecule Instant coffee was developed in 1901 by a Japanese chemist, but did not gain popularity until World War I when it was shipped to U.S. troops overseas. In 1906, a German chemist developed a process for removing caffeine during processing, producing the first decaffeinated coffee. The decaffeination process often uses controversial chemicals as solvents to extract over 99% of the caffeine. For example, the most common organic solvent used to decaffeinate coffee is methylene chloride. This chemical was banned for use in hairspray by the FDA in 1989 because it caused cancer in laboratory animals when inhaled and was additionally implicated in harming the ozone layer. Another common organic solvent, ethyl acetate, is considered less toxic than methylene chloride, but is still somewhat controversial. Proponents of these decaffeination methods maintain that the solvent is thoroughly rinsed from the beans during processing. The other commonly used decaffeination solvent is water. The caffeine is leached into the water and subsequently filtered through caffeine-binding charcoal. Decaffeination using a water solvent is more costly than chemical solvent extraction because the caffeine cannot be recovered. Chemical solvent caffeine that is recovered is used mainly in soft drinks and in some cold and headache medications. Whether you call it java, joe, or mocha, coffee is one of the most important and popular nonalcoholic beverages on the market. References, Websites, and Further Reading Levetin, Estelle, and Karen McMahon. 1999. Plants and society, 2d ed. New York: McGraw-Hill Companies, pp. 259-63. Simpson, B.B., and Molly C. Ogorzaly. 2001. Economic botany: Plants in our world, 3d ed. New York: McGraw-Hill Companies. Coffee Science Information Centre: Coffee and Caffeine Health Information http://www.cosic.org/ "Coffee," Microsoft® Encarta® Online Encyclopedia 2000. © 1997-2000, Microsoft Corporation. http://encarta.msn.com New York Botanical Garden Synopsis of Neotropical Rubiaceae Genera http://www.nybg.org/bsci/res/delpic2.html National Geographic On-line: Coffee http://www.nationalgeographic.com/coffee/ Related Reading in Stern, Introductory Plant Biology, 8th Edition Chapter 1: What Is Plant Biology? Human and Animal Dependence on Plants, pp. 4-7 Chapter 2: The Nature of Life The Elements: Units of Matter, pp. 15-17 Chemical Components of Cells (organic and inorganic), pp. 21-22 Lipids, p. 23 Enzymes, p. 26 Chapter 6: Stems Origin and Development of Stems, including woody twig labeled (external), pp. 85-86. Chapter 8: Flowers, Fruits, and Seeds Differences Between Monocots and Dicots, including Table 8.1, pp.129-30. Structure of Flowers, pp. 129-32 Fruits: Fruit Regions; Kinds of Fruits, pp. 132-39 Seeds: Structure; Germination, pp. 143-45 Chapter 16: Plant Names and Classification Common Names and the Binomial System of Nomenclature, pp. 268-70 Chapter 24: Flowering Plants and Civilization Origin of Cultivated Plants, pp. 436-37 Coffee and Caffeine, pp. 456-57