Macadamia, Macadamia integrifolia, and Macadamia tetraphylla, (also spelled macademia) are medium evergreen trees, growing to 25 – 30 feet. They are members of the protea family and come from tropical Eastern Australia, New Caledonia and Sulawesi. Only two of the several species of the Macadamia family are used commercially. All other species are poisonous or inedible. The indigenous people of Australia have used macadamias for thousands of years, leaching the nuts of the toxic species to remove the cyanogenic glycocides in order to make the nuts edible.
Trees are mostly grown from grafts and do not produce nuts for seven to ten years. Once they produce, they may continue to bear nuts for over 100 years. They grow best in fertile soil and in moderate temperatures. They are frost intolerant when young, but mature trees can tolerate light frost. Shallow-rooted, the trees are blown down easily in storms. The shell surrounding the nuts is extremely hard and a bit challenging to crack. (A blunt instrument is needed, such as a hammer, anvil or heavy rock.)
Europeans first learned about wild macadamias in the 1820s. The indigenous peoples later gathered and traded them with the Europeans. The first commercial plantations in Australia were established in the 1880s. The trees were taken to Hawaii in the 1880s to use as a windbreak for sugarcane, which seems odd given the fact that they blow down easily.
In 1910 the Hawaiian Agricultural Experiment station encouraged growing macadamias in the Kona region of Hawaii to supplement the coffee crop, but the first plantation began in 1925 in Honolulu. It was because of the Hawaiian crop that macadamias became known internationally. While Hawaii was the largest producer for many years, Australia is once again the largest producer, shipping over 40,000 tons of the nuts annually. Interestingly enough, the macadamia is the only native Australian plant food that is produced and exported in volume.
Not only are they delicious, macadamias also happen to be nutritious. They have the highest volume of monounsaturated fats of all known nuts. They contain 9% protein, as well as calcium, phosphorus, potassium, selenium, iron, thiamine, riboflavin and niacin. Knowing this, you needn’t feel guilty when a bowl of roasted, salted macadamias just begs to be eaten. All pounds gained will be healthy.
Macadamia oil is very desirable in cosmetics, as its high content of palmitoleic acid makes it a botanical alternative to mink oil. In addition to that, it has high oxidative stability, excellent in skincare products.