Macadamia oil (or macadamia nut oil) is the non-volatile oil collected 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, native to northeastern New South Wales and central and southeastern Queensland specifically. Two species of the genus ...

(''Macadamia integrifolia''), a native Australian plant. It is used in

food Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is in ...

as a frying or salad oil, and in

cosmetic Cosmetic may refer to: *Cosmetics, or make-up, substances to enhance the beauty of the human body, apart from simple cleaning *Cosmetic, an adjective describing beauty, aesthetics, or appearance, especially concerning the human body *Cosmetic, a t ...

formulations as an

emollient A moisturizer, or emollient, is a cosmetic preparation used for protecting, moisturizing, and lubricating the skin. These functions are normally performed by sebum produced by healthy skin. The word "emollient" is derived from the Latin verb ''m ...

fragrance An aroma compound, also known as an odorant, aroma, fragrance or flavoring, 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 sufficiently v ...

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, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its dens ...

of 900–920 and a flash point of over 300 °C (572 °F). Oil accumulation does not commence 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. As with many oil seeds, the protein is low in

methionine Methionine (symbol Met or M) () is an essential amino acid in humans. As the precursor of other amino acids such as cysteine and taurine, versatile compounds such as SAM-e, and the important antioxidant glutathione, methionine plays a critical ...

. Fresh kernels contain up to 4.6% sugar, mostly non-reducing 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). The fatty acid composition and the absence of cholesterol may lead to the promotion of macadamias as a high-energy health food. The major volatile components in roasted macadamia kernels are apparently similar to those found in other roasted nuts, although little detailed information is available.

Uses in food

Macadamia oil can be used for frying due to its high heat capacity along with other properties useful as an edible oil: * Contains up to 85%

monounsaturated fat Monounsaturated fats are fatty acids that have one double bond in the fatty acid chain with all of the remainder carbon atoms being single-bonded. By contrast, polyunsaturated fats have more than one double bond. Molecular description Fatty acid ...

s * Unrefrigerated

shelf life Shelf life is the length of time that a commodity may be stored without becoming unfit for use, consumption, or sale. In other words, it might refer to whether a commodity should no longer be on a pantry shelf (unfit for use), or no longer on a ...

of one to two years * Smoke point of 210 °C (410 °F) * Flashpoint of over 300 °C (572 °F)

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. In chemical terms, oleic acid is classified as a monounsaturated o ...

, 19%

palmitoleic acid Palmitoleic acid, or (9''Z'')-hexadec-9-enoic acid, is an omega-7 monounsaturated fatty acid (16:1n-7) with the formula CH3(CH2)5CH=CH(CH2)7COOH that is a common constituent of the glycerides of human adipose tissue. It is present in all tiss ...

, 1-3%

linoleic acid Linoleic acid (LA) is an organic compound with the formula COOH(CH2)7CH=CHCH2CH=CH(CH2)4CH3. 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. ...

and 1-2%

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

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

polyunsaturated fat Polyunsaturated fats are fats in which the constituent hydrocarbon chain possesses two or more carbon–carbon double bonds. Polyunsaturated fat can be found mostly in nuts, seeds, fish, seed oils, and oysters. "Unsaturated" refers to the fact t ...

content.

References

External links

How Products are Made: Macadamia Nut
{{fatsandoils Cosmetics chemicals Cooking oils Macadamia Nut oils