Photo © Steven Foster
C. sinensis is a subtropical tree that can grow to 25 feet high.1 The small white flowers are followed by fruit, sometimes called sweet orange, that is 2 to 4 inches in diameter.1 The season for oranges begins in November, with the peak in early spring.2 It is the most popular citrus fruit in the world.3,4
History and Cultural Significance
The orange traces its roots to China and India.4 The name is derived from a Sanskrit term nagarunga meaning fruit favored by elephants. Ancient legend states that Gaea, the Greek goddess of earth and fertility, presented Zeus a “golden apple” on their wedding day. This fruit was thought to be an orange.2 The fruit spread to the Mediterranean area and other parts of Europe in the 1400s.4 Orange flowers were a symbol of love in medieval times. The fruit itself was used in wedding ceremonies and given as gifts to the newlyweds as a symbol of prosperity and fertility.2 Christopher Columbus brought the orange to Haiti on his second voyage in 1493. Spanish missionaries took them from the Caribbean to Florida in the early 1500s where they became a huge industry. Missionaries also began the rival California industry in the 1700s.4 The orange is a traditional Chinese symbol of good luck and is a mainstay of the Chinese New Year.2
Almost 80% of oranges are used for orange juice. However, the juice and pulp have been used as a digestive aid, to relieve gas pains, swelling and constipation.2,5 Oranges also contain vitamins A, B-complex and C, flavonoids and antioxidants.2,6,7 The fruit also has a high folate content.8 The dried orange peel has been used to treat coughs and colds.5,7
The essential oil extracted from the peel through either cold expression or steam distillation, has a sweet citrus aroma.7 The orange scent is a combination of lemon-scented citral and limonene, lavender-scented linalool and pine-scented terpineol. Topical applications of the essential oil are used to soften dull and oily complexions and soothe mouth ulcers. The essential oil is also used in flavoring pharmaceuticals, food and drinks and as a fragrance in soaps, detergents, cosmetics and perfumes.6
Citrus fruits, including C. sinensis, have been investigated as a delivery system for vaccines; the fruits were injected with the vaccine and then eaten.9 Most modern research, however, is focused on new efficient ways to grow, protect and harvest oranges.
Brazil is the largest orange-producing country, with nearly a third of the world market. Other heavily involved countries are the United States, Mexico, China and India. Over 140 billion pounds of oranges were cultivated in 2002, which is a 15% increase over the previous decade. In order to continue this expansion, growers will not only need more land, but continued research to increase their present yield.3
1 Morton J. Orange. In: Morton J. Fruits of Warm Climates. Miami, FL. 1987. Available at: http://www.hort.purdue.edu/newcrop/morton/orange.html. Last update: May 7, 2001. University of Purdue website. Accessed on November 17, 2005.
2 Onstad D. Whole Foods Companion: A Guide for Adventurous Cooks, Curious Shoppers & Lovers of Natural Foods. White River Junction, VT: Chelsea Green Publishing Company; 1996.
3 Citrus: Lemon, Lime, Orange, Tangerine, Grapefruit - Citrus spp. Available at: http://www.uga.edu/fruit/citrus.htm#PRODUCTION. University of Georgia website. Accessed on November 17, 2005.
4 Davidson A. The Oxford Companion to Food. New York: Oxford University Press; 1999.
5 Wood R. The New Whole Foods Encyclopedia. New York: Penguin Books; 1999.
6 Rinzler C. The New Complete Book of Herbs, Spices, and Condiments: A Nutritional, Medical, and Culinary Guide. New York: Checkmark Books; 2001.
7 Lawless J. The Encyclopaedia of Essential Oils: The Complete Guide to the Use of Aromatics in Aromatherapy, Herbalism, Health & Well-being. Rockport, MA: Element; 1992.
8 Crowel PL, Gould MN. Chemoprevention and therapy of cander by d-limonene. Crit Rev Oncog. 1994; 5:1-22. Cited by Rakel, D. Integrative Medicine. Philadelphia: Saunders; 2003.
9 Hu R, Wei H, Chen S, et al. Construction of the plant expression vector with hepatitis a capsid protein fusion gene and genetic transformation of Citrus sinensis Osbeck[In Chinese]. Yi Chuan. July 2004; 26(4):425-31.