Macadamia oil, also known as macadamia nut oil, is a non-

volatile oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...

extracted from the nuts of the

macadamia ''Macadamia'' is a genus of four species of trees in the flowering plant family Proteaceae. They are indigenous to Australia—specifically, northeastern New South Wales and central and southeastern Queensland. Two species of the genus are comm ...

tree (''Macadamia integrifolia''), indigenous to

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. This oil is used in culinary applications as a frying or salad oil, and in

cosmetics Cosmetics are substances that are intended for application to the body for cleansing, beautifying, promoting attractiveness, or altering appearance. They are mixtures of chemical compounds derived from either Natural product, natural source ...

for its emollient properties and as a

fragrance An aroma compound, also known as an odorant, aroma, fragrance, flavoring or flavor, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficien ...

fixative.

Description

Fruits

''Macadamia integrifolia'' is an Australian tree with holly-like leaves that grows well in a moist, organic soil and can withstand temperatures as low as −4.4 °C (24 °F). Seedlings bear in 5–7 years. The fruit is borne in a case enclosing an extremely hard spherical nut. The kernel is whitish, sweet and eaten raw or roasted. The flowers are white to cream and the leaves are in whorls of three. Propagation is by seed, grafting or air layering. It is grown commercially. Common names of the trees are the Australian nut or the Queensland nut. Species that are “smooth shelled macadamia” are called ''Macadamia integrifolia'' and “rough shelled macadamia” are called ''Macadamia tetraphylla''. ''Macadamia ternifolia'' is also the name used for ''M. integrifolia''. ''Macadamia integrifolia'' is native to Australia where it grows in rain forests and close to streams. ''Macadamia tetraphylla'' is native to Southeastern Queensland and Northeastern New South Wales.

Oil

The oil content ranges from 65% to 75% and sugar content ranges from 6% to 8%. These factors result in variable colors and texture when the nuts are roasted under the same conditions. Macadamia oil is liquid at room temperature. The refined oil is clear, lightly amber-colored with a slightly nutty smell. It has a

specific gravity Relative density, also called specific gravity, is a dimensionless quantity defined as the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for solids and liquids is nea ...

of 900–920 and a flash point of over 300 °C (572 °F). Oil accumulation does not occur until the nuts are fully grown and the shell hardens. It accumulates rapidly in the kernel during late summer when the reducing sugar content decreases. The composition of mature, roasted and salted macadamia nuts is shown. Fresh kernels contain up to 4.6% sugar. The oil consists of mainly unsaturated fatty acids and is similar in both species, although the proportion of unsaturated to saturated fatty acids appears to be slightly higher in ''M. integrifolia'' (6.2:1 compared with 4.8:1).

Uses in food

Macadamia nut oil possesses properties conducive to high-heat cooking, such as a high

smoke point The smoke point, also referred to as the burning point, is the temperature at which an oil or fat begins to produce a continuous bluish smoke that becomes clearly visible, dependent upon specific and defined conditions. This happens when one or ...

and resistance to oxidative degradation. These qualities suggest its suitability for culinary techniques involving heat. A study examining the blend of refined bleached deodorized palm olein oil and Macadamia integrifolia oil for deep-fat frying found that the latter displayed enhanced stability and reduced oxidation, highlighting its potential for high-temperature cooking applications. Macadamia nut oil is primarily used in unheated forms, such as dressings and drizzles. This is based on the premise that its unheated use better preserves the oil's delicate flavor and nutritional components. Therefore, while macadamia nut oil's heat tolerance supports its use in cooking, it is often preferred in raw applications to fully leverage its unique flavor profile.

Fatty acids

Macadamia oil contains approximately 60%

oleic acid Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish due to the presence of impurities. In chemical terms, oleic acid is cl ...

, 19% palmitoleic acid, 1-3%

linoleic acid Linoleic acid (LA) is an organic compound with the formula . Both alkene groups () are ''cis''. It is a fatty acid sometimes denoted 18:2 (n−6) or 18:2 ''cis''-9,12. A linoleate is a salt or ester of this acid. Linoleic acid is a polyunsat ...

and 1-2%

α-linolenic acid α-Linolenic acid, also known as ''alpha''-linolenic acid (ALA) (from Greek ''alpha'' denoting "first" and ''linon'' meaning flax), is an ''n''−3, or omega-3, essential fatty acid. ALA is found in many seeds and oils, including flaxseed, ...

. The oil displays chemical properties typical of a vegetable triglyceride oil, as it is stable due to its low

polyunsaturated fat In biochemistry and nutrition, a polyunsaturated fat is a fat that contains a polyunsaturated fatty acid (abbreviated PUFA), which is a subclass of fatty acid characterized by a backbone with two or more carbon–carbon double bonds. Some polyunsa ...

content.

References

{{fatsandoils Cosmetics chemicals Cooking oils Macadamia Nut oils