Macadamia Nut



Background

In the world of nuts and berries, macadamia nuts are almost as precious as gold. These delicious, exotic nuts with their rich flavor and oil are considered delicacies and are served as dessert nuts. They are popular gifts at holiday times, both alone and when covered with chocolate. They are prized as souvenirs from Hawaii, and, thanks to Mrs. Fields' cookies, macadamia and chocolate chip cookies have brightened many afternoons at the local mall.

Macadamia nuts are associated in the minds of most Americans with Hawaii. Macadamias are a commercial crop in Hawaii, but they originated in northeastern Australia in the rain forests along the coast. The tree is from the family Protaceae and is one of about 10 species of which two grow best as commercially productive plants. The Macadamia integrefolia produces nuts with smooth shells, and the Macadamia tetraphylla has rough-shelled nuts.

Macadamia trees produce throughout their lives but they are slow growing. The demand for the rich nuts has outstripped growers' ability to produce them. Consequently, growers in many other countries including New Zealand, Zimbabwe, Malawi, South Africa, Kenya, Israel, Guatemala, Brazil, Mexico, and Costa Rica have begun planting large orchards. In the United States, California and Florida boast macadamia crops, along with Hawaii.

History

The macadamia nut was discovered by British colonists in Queensland, Australia, in 1857. Walter Hill, who was the Director of the Botany Garden in Brisbane, found one of the nuts, cracked it open using a vise, and planted the seed. This "first" macadamia nut tree is still growing and producing nuts, although typically the trees only produce for about 70 years.

Hill had been traveling on a botanical expedition with Baron Ferdinand von Mueller, who is considered the father of Australian botany and who held the post of Royal Botanist in Melbourne at the time. He is credited with naming the tree after Scotsman John Macadam, a friend, physician, and member of the Philosophical Institute of Victoria. Mr. Macadam never tasted the nut that bears his name after a shipboard injury caused his premature death en route to New Zealand.

Of course, the trees had long been known to the native Australian aborigines who called the macadamia trees kindal kindal and who feasted on the nuts in winter. The colonists took the tree to their hearts and began to learn to propagate it. The first known macadamia orchard consisted of 250 trees planted in 1890 on the Frederickson Estate in New South Wales, Australia. The tree was heavily cultivated and hybrids were grown from seeds and, more often, by grafting. Australia remains one of the world's major producers.

The macadamia migrated to Hawaii courtesy of William Herbert Purvis who gathered macadamia nuts near Mount Bauple in Queensland, Australia, and brought them to Hawaii's Big Island in 1882. He nurtured the imported nuts and planted them as seedlings in Kukuihaele, Hawaii. One of Purvis's original seedlings is also still growing and producing nuts.

Today, Mauna Loa Macadamia Nut Corporation is the largest manufacturer of macadamia nuts in the world. The firm's plantation was founded in 1948, the trees began to bear fruit in 1954, and the first commercial crop was harvested and processed in 1956. Over 10,000 acres of rich, volcanic soil host Mauna Loa's orchards. The single largest planting is not in Hawaii but on 3,700 acres in South Africa. The hybrid grown in New Zealand produces the most expensive macadamia nuts in the world; the Beaumont sp. does not drop its macadamias, so they are expensive to harvest and are also among the finest in flavor.

Raw Materials

The raw materials needed for commercial production of macadamia nuts are the nuts themselves, as well as salt and oil.

Design

Macadamia nuts are sold in jars and cans for home consumption. These nuts have been roasted in oil in the factory and salted. Unsalted nuts are also packed for commercial use, primarily by bakeries. The flavor of the nuts is well suited for use in many kinds of desserts. Design can become elaborate if the nuts are used in candies, cookies, and other products. A wide variety of desserts, souvenirs of the islands, and other treats containing macadamias are available on the market; some are byproducts of the macadamia nut processors, but, more often, other firms use the nuts as ingredients in their own product lines.

The Manufacturing
Process

Cultivation

In the factory

Quality Control

The cultivation and processing of macadamia nuts are persnickety by definition. Their unusual growing characteristics and their devilishly hard shells need careful attention. Quality control is essential in the orchard to produce nut clusters and collect them in a timely manner (and as cost effective as possible). During processing, machines are essential to remove both the husks and the hard shells, but observation is

The nuts pass through steel rollers that counter-rotate and exert a pressure of 300 lb per sq in (21 kg per sq cm) on the shells, causing them to crack without damaging the kernels inside. The kernels passed through a series of blowers and trommels or gravity separators with holes that remove dust, dirt, any remaining bits of husk, or nuts that are substandard. Uncracked nuts are collected and recycled through the crackers. Optical devices inspect the nuts and sort them by color. Quality control inspectors also observe the passing flow of kernels and sort them by hand.
The nuts pass through steel rollers that counter-rotate and exert a pressure of 300 lb per sq in (21 kg per sq cm) on the shells, causing them to crack without damaging the kernels inside. The kernels passed through a series of blowers and trommels or gravity separators with holes that remove dust, dirt, any remaining bits of husk, or nuts that are substandard. Uncracked nuts are collected and recycled through the crackers. Optical devices inspect the nuts and sort them by color. Quality control inspectors also observe the passing flow of kernels and sort them by hand.
provided throughout by quality inspectors and by computer-controlled optical devices.

Byproducts/Waste

Kernels are also ground and processed to produce macadamia nut oil as a byproduct. Bad kernels are not wasted and are often used as animal feed. The shells and other waste comprise almost 70% by weight of the macadamia nuts, and they also are collected for other uses. The countries and regions that produce macadamias also usually grow coffee, and shells can be burned as a wood substitute in coffee roasting. The husks are ground to produce organic waste for gardening, for mulch in the nut tree orchards, and for chicken litter that, after use, returns to the orchard for use as fertilizer.

The Future

Macadamia nuts are an excellent source of iron, calcium, vitamin B, and phosphorus. Although they contain 73-80% fat, the fat is monosaturated or "good" and as acceptable as olive oil in many diets. Although macadamias have many healthful properties, their unusually rich flavor, crunch, and comingling with chocolate in a bounty of forms make them favorites among gourmets and snackers alike. Good taste is always in style, so the future of the macadamia nut is promising indeed.

Where to Learn More

Books

Thomson, Paul H. "Macadamia." In Nut Tree Culture in North America. Richard A Jaynes, ed. Hamden, Connecticut: The Northern Nut Growers Association, Inc. 1979, pp. 188-202.

Periodicals

Sokolov, Raymond "Tough Nuts: Despite Some Superficial Similarities, Brazil Nuts And Macadamia Nuts Present A Study In Contrasts." Natural History (March 1985): 78.

Other

California Macadamia Nut Society. http://users.aol.com/TecterJS/themac.html/ .

Hamakua Macadamia Nut Company. http://206.127.252.21/hawnnut/ .

Macadamia Miravalles S.A., Costa Rica. http://macadamia.co.cr/ .

MacNut Farms & Café. http://macnut.co.nz/ .

Mauna Loa Macadamia Nut Corporation. http://www.maunaloa.com/ .

Gillian S. Holmes



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