March, 2002: Hawaii
Although native to Australia, macadamia nuts are a main source of revenue
for the Hawaiian Islands. Introduced in the mid-1800s as an ornamental,
the macadamia tree prospers in Hawaii's well-drained soils. From family-owned
orchards of but a few acres to the corporate orchards owned by Blue Diamond,
macadamias are big business for the Aloha State. Most recently, researchers
at the University of Hawaii have been studying the cholesterol-lowering
effects of a diet that includes macadamia nuts.
Macadamia is both the common name and the proper Latin genus name for Macadamia integrifolia, a plant in the Proteaceae family. Proteaceae is a family of dicots composed of about 77 genera and 1,600 species. General characteristics of the Proteaceae include sessile leaves and flowers borne on a showy inflorescence.
While Hawaii formerly produced about 90% of the world's macadamia nuts, that amount has dropped within the last decade, largely due to mass plantings in other countries where land is less expensive and yet suitable for macadamia nut growth. Today, Hawaii produces about 40% of the world's macadamia nuts, and Australia and New Zealand another 40%, with the remaining 20% produced in South Africa and various other tropical areas.
 Cultivator with bag of macadamia nuts. (Photo courtesy of John Peterson.) |
Growing macadamias requires an initial investment that does not yield fruits or profits for some time. It takes about 10 years before the trees begin to produce nuts in any quantity, each tree yielding 150 pounds of nuts (including the shells, etc.) over a six-month period. Harvesting is also an expensive process. Commencing sometime in June or July, crops are gathered by hand. The fruits are husked with a mechanical husker and thoroughly dried. Reducing the moisture from about 20% to 0% facilitates the removal of the shell, which requires 300 pounds of pressure per square inch to break! Additionally, drying enables the nut to be stored for longer periods of time without the risk of spoiling. The mechanically cracked shells are separated from the inner nuts prior to grading the final product. Whole macadamias demand the highest prices, while those cracked or fragmented during shelling are sold for baking and for making candy and ice cream.
Macadamia nuts are receiving a lot of recognition lately as an ingredient in cosmetics, a healthful snack, and a source of cooking oil. Per 100 grams of macadamia nut consumed, a person takes in about 700 calories, just over 8 grams of protein, almost 74 grams of fat, 14 grams of carbohydrates, and about 5 grams of fiber. Additionally, the nuts have a high mineral content. The same 100 grams of nuts also yields 70 mg of calcium, 116 mg of magnesium, 136 mg of phosphorus, and a whopping 368 mg of potassium.
 Macadamia nuts for sale in a supermarket. (Photo copyright Erica Kipp.) |
While the fat content of macadamia nuts seems high (about 74%), researchers and medical doctors at the University of Hawaii in Honolulu point out that 80% of these fat grams are monounsaturated fats. Based on a recent study, a diet based on macadamia nuts (one high in monounsaturated fats) was just as effective in lowering blood serum cholesterol levels as the moderately low-fat diet recommended by the American Heart Association.
Information related to the research, sales, and marketing of macadamia nuts is exchanged annually at meetings of The Hawaii Macadamia Nut Association, last held in July 2000. In addition to the ground-breaking cholesterol-lowering research, the president of Blue Diamond Growers was happy to report $500 million in annual sales from macadamia nuts and other nuts to over 100 markets globally. Blue Diamond also proudly supplies NASA astronauts with macadamia nuts, an approved snack for shuttle flights.
As if these were not enough good reasons to eat macadamia nuts, they taste great besides!
References, Websites, and Further Reading
Curb, J.D., et. al. 2000. Serum lipid effects of a high-monounsaturated-fat diet based on macadamia nuts. Arch Intern Med 160, pp. 1154-58.
Levetin, Estelle, and Karen McMahon. 1999. Plants and Society, 2d ed. New York: McGraw-Hill Companies.
Simpson, B.B., and Molly C. Ogorzaly. 1995. Economic Botany: Plants in Our World, 2d ed. New York: McGraw-Hill Companies.
www.nasa.gov
Website of the National Aeronautics and Space Administration
www.americanheart.org
Website of the American Heart Association
Related Reading in Stern, Kingsley R. 2000. Introductory Plant Biology,
8th ed. New York: McGraw-Hill Companies.
Chapter 2: The Nature of Life
Carbohydrates, p. 22
Lipids (mono- and polyunsaturated), p. 23
Chapter 8: Flowers, Fruits, and Seeds
Inflorescence types, pp. 129-32; fig. 8.7
Chapter 16: Plant Names and Classification
Common names and Latin names, pp. 268-77
McGraw-Hill Higher Education is one of the many fine businesses of The McGraw-Hill Companies.
If you have a question or a problem about
a specific book or product, please fill out our Product
Feedback Form.
For further information about this site contact mhhe_webmaster@mcgraw-hill.com
or let us know what you think by filling out our Site
Survey.
