Macadamia

Macadamia is a genus of four species of trees indigenous to Australia, and constituting part of the plant family Proteaceae. They are native to north eastern New South Wales and central and south eastern Queensland. Three species of the genus are commercially important for their fruit, the macadamia nut (or simply macadamia), with a total global production of 160,000 tonnes (180,000 short tons) in 2015. Other names include Queensland nut, bush nut, maroochi nut, bauple nut, and Hawaii nut. In Australian Aboriginal languages, the fruit is known by names such as bauple, gyndl, jindilli, and boombera.

History

The macadamia tree is native to Australia, where it has been a source of food for Aboriginal peoples for thousands of years. The tree was first discovered by Europeans in 1828, when explorer and botanist Allan Cunningham came across it in Queensland. The macadamia nut was introduced to the international market in the early 20th century, and is now grown commercially in a number of countries around the world, including South Africa, Israel, and the United States, particularly in the state of Hawaii.

Cultivation

Macadamia trees are usually propagated by grafting, and do not begin to produce commercial quantities of seeds until they are 7–10 years old, but once established, may continue bearing for over 100 years. Macadamias prefer fertile, well-drained soils, a rainfall of 1,000–2,000 mm (40–80 in), and temperatures not falling below 10 °C (50 °F) (although once established they can withstand light frosts), with an optimum temperature of 25 °C (75 °F). The roots are shallow and trees can be blown down in storms; they are also susceptible to Phytophthora root disease.

Uses

The macadamia nut has a hard, woody shell that must be cracked open to reveal the edible kernel. The kernel is rich in oil, and is used in cooking, for oil extraction, and in confectionery. The nut's high oil content makes it a valuable source of food energy. Macadamia oil is also used in cosmetics due to its stability and high monounsaturated fat content.

Health Benefits

Macadamia nuts are a rich source of Vitamin A, iron, protein, thiamin, riboflavin, niacin, and folates. They also contain moderate amounts of zinc, copper, calcium, phosphorus, potassium, and magnesium. Macadamia contains antioxidants like polyphenols, Amino acids, flavones, and selenium. It is also a good source of carbohydrates like sucrose, fructose, glucose, maltose, and some starch-based carbohydrates.

See Also

• List of culinary nuts
• Proteaceae
• Allan Cunningham (botanist)
• Hawaii