Macadamia integrifolia seed oil: properties, uses, pros, cons, safety

Fixed oil obtained from the seeds/nuts of Macadamia integrifolia (family Proteaceae), used as an emollient and skin conditioning agent; in suitable grades, also used as an edible oil

Synonyms: macadamia seed oil; macadamia nut oil; refined macadamia oil; cold-pressed macadamia oil (grade-dependent)
INCI / functions: skin conditioning (emollient)

Definition

Macadamia integrifolia seed oil is a vegetable oil composed mainly of triglycerides with a distinctive lipid profile: beyond oleic acid, it often contains a relatively high share of palmitoleic acid (C16:1), a feature that contributes to a generally more silky and “gliding” skin feel than many common oils. Depending on cultivar, origin, and processing (refined vs cold-pressed), color, residual odor, and key parameters such as acid value and peroxide value vary, with impacts on stability and sensorial repeatability.

From a nutritional perspective (when intended for food use), it is an oil dominated by MUFA (monounsaturated fatty acids) and relatively low in PUFA (polyunsaturated fatty acids) compared with many vegetable oils; SFA (saturated fatty acids) are present but typically represent a smaller fraction. The lower PUFA fraction tends to support better oxidative stability, although initial raw material quality and storage conditions remain decisive.

Main uses

Food.
In food-grade quality, macadamia oil is used as an edible oil and lipid ingredient, often appreciated for a mild organoleptic profile and use as a seasoning oil or in culinary preparations. Suitability depends on quality specifications and compliance (limits on oxidation, contaminants, and identity parameters). Allergen management is relevant: macadamia is a tree nut and requires appropriate allergen-risk management and labeling in food applications.

Cosmetics.
In cosmetics it is mainly used as an emollient in creams, lotions, body oils, massage products, cleansing oils, and lip products. It is selected to improve spreading and comfort, reducing drag and supporting a soft after-feel without being excessively heavy. The meaningful palmitoleic content can contribute to a more “skin-affine” sensorial profile in certain leave-on products, making it attractive for nourishing and softening concepts.

In haircare it can be used in masks, pre-shampoo oils, and some leave-on products to increase shine and perceived softness. As with other oils, potential “weight” depends on dose, hair type, and overall formula architecture: on fine hair, lower levels or blends with lighter esters are often preferable.

Medicine.
Not a therapeutic active; it may appear as a vehicle/emollient in specific finished products.

Pharmaceutical.
May be used as a lipid excipient/vehicle in topical (and in specific contexts also oral) preparations when compliant with required specifications; in such cases, oxidation, acidity, and purity controls are essential.

Industrial use.
Use is primarily within personal care; other uses depend on technical specifications and grade availability.

Calories (energy value)

Identification data and specifications

Chemical-physical properties (indicative)

Indicative lipid composition

Functional role and practical mechanism

Formulation compatibility

In O/W and W/O emulsions, macadamia oil is generally easy to incorporate and contributes a more silky touch; compatibility depends mainly on oil-phase design and emulsifier choice. For leave-on formulas, it is recommended to manage oxidative stability through: selecting low-PV lots, controlling exposure to light/heat/oxygen, and—if consistent with the project and regulatory context—using a suitable antioxidant strategy.

In anhydrous systems (body oils, massage oils, lip products), it can represent a substantial share of the oil phase. The most common issues relate to odor/color drift over time (oxidation) and sensorial lot-to-lot variability if specifications are not well defined (fatty acid profile, AV/PV, refractive index). In haircare, to limit build-up and weight, it is often used at moderate levels or blended with lighter esters.

For products aimed at acne-prone skin, evaluation should be done on the finished product: perceived oiliness depends on dose, total oil phase, sensorial polymers, and use pattern.

Use guidelines (indicative)

Quality, grades, and specifications

Safety, regulatory, and environment

In cosmetics, safety is assessed on the finished product (use area, frequency, population). Macadamia oil is widely used as an emollient; however, sensitization can occur in predisposed individuals, and allergen management is particularly relevant in food applications and, as a precaution, also for leave-on products intended for sensitive consumers.

In manufacturing, applying GMP (Good manufacturing practice; benefit: reduces variability and contamination) improves control and repeatability. Where adopted as an approach, HACCP (Hazard analysis and critical control points; benefit: strengthens prevention and control at critical process points) supports preventive management of sensitive points.

Formulation troubleshooting

Conclusion

Macadamia integrifolia seed oil is valued for a typically silky and comfortable sensorial profile, supported by a meaningful palmitoleic fraction. It is used as an emollient in many leave-on and anhydrous products, and it is versatile in haircare as well. Quality and formulation success depend critically on specifications (PV/AV, identity parameters, fatty acid profile) and rigorous management of oxidative stability across the supply chain and storage.

Mini-glossary

MUFA: monounsaturated fatty acids; health note: when replacing some saturated fats, they may support a more favorable dietary lipid profile within the overall diet.
PUFA: polyunsaturated fatty acids; health note: include essential fatty acids such as linoleic; more oxidation-prone, so oil stability is a technical focus.
SFA: saturated fatty acids; health note: excessive dietary intake is often associated with less favorable profiles; in vegetable oils they are often minor but relevant for texture.
Peroxide value (PV): indicator of primary oxidation in oils.
Acid value (AV): index of free fatty acids; linked to quality and hydrolysis.
GMP: Good manufacturing practice; benefit: reduces variability and contamination.
HACCP: Hazard analysis and critical control points; benefit: strengthens prevention and control at critical process points.

Studies

This oil contains moderate quantities of tocopherols and phenolic compounds and is quite similar to walnut oil for its antioxidant properties (1).

The seed oil in Macadamia integrifolia contains about 30% palmitoleic acid (16:1(Delta9)) (2).

References_____________________________________________________

(1) Shakerardekani A, Karim R, Ghazali HM, Chin NL. Textural, rheological and sensory properties and oxidative stability of nut spreads—a review. Int J Mol Sci. 2013 Feb 20;14(2):4223-41. doi: 10.3390/ijms14024223. 

Abstract. Tree nuts are rich in macro and micronutrients, phytochemicals, tocopherols and phenolic compounds. The development of nut spreads would potentially increase the food uses of nuts and introduce consumers with a healthier, non-animal breakfast snack food. Nut spreads are spreadable products made from nuts that are ground into paste. Roasting and milling (particle size reduction) are two important stages for the production of nut spreads that affected the textural, rheological characteristic and overall quality of the nut spread. Textural, color, and flavor properties of nut spreads play a major role in consumer appeal, buying decisions and eventual consumption. Stability of nut spreads is influenced by its particle size. Proper combination of ingredients (nut paste, sweetener, vegetable oil and protein sources) is also required to ensure a stable nut spread product is produced. Most of the nut spreads behaved like a non-Newtonian pseudo-plastic fluid under yield stress which help the producers how to start pumping and stirring of the nut spreads. Similar to other high oil content products, nut spreads are susceptible to autoxidation. Their oxidation can be controlled by application of antioxidants, using processing techniques that minimize tocopherol and other natural antioxidant losses.

(2) Gummeson PO, Lenman M, Lee M, Singh S, Stymne S. Characterisation of acyl-ACP desaturases from Macadamia integrifolia Maiden & Betche and Nerium oleander L. Plant Sci. 2000 May 15;154(1):53-60. doi: 10.1016/s0168-9452(99)00268-x.

Abstract. The seed oil in Macadamia integrifolia contains about 30% palmitoleic acid (16:1(Delta9)) and Nerium oleander about 12% isoricinoleic acid (Delta9-hydroxy-18:1(Delta12)). It has been shown that palmitoleic acid can be produced by acyl-acyl carrier protein (ACP) desaturases and it has also been shown that fatty acid hydroxylation can occur via direct substitution of a hydrogen atom. Therefore it seemed possible that the enzymes responsible for the making of these unusual fatty acids in M. integrifolia and N. oleander were of acyl-ACP desaturase type. Extracts from developing M. integrifolia developing seeds showed a relative ratio of 16:0-ACP to 18:0-ACP desaturation that was about 13 times higher than in sunflower seeds. N. oleander seed extracts catalysed conversion of 18:0-ACP to 18:1(Delta9) but only trace amounts of Delta9-hydroxy fatty acids were formed. A total of four cDNAs were isolated from developing seeds, of both species, using a fragment isolated with PCR amplification. The M. integrifolia acyl-ACP desaturase cDNA was expressed in Escherichia coli. A partly purified fraction of the enzyme showed a 16:0-ACP to 18:0-ACP desaturation ratio about 90-fold less than that in the Macadamia extracts. Expressed N. oleander acyl-ACP desaturase cDNAs showed predominantly 18:0-ACP desaturase activity and no hydroxylase activity. Thus it is not likely that any of the four acyl-ACP desaturases cloned from M. integrifolia or N. oleander is involved in the production of unusual fatty acids.