The essential oil obtained from the leaves of Citrus x aurantium (petitgrain) is composed predominantly of monoterpenes, followed by sesquiterpenes. A study published in BMC Complementary Medicine and Therapies (2024) identified 35 volatile compounds and compared three extraction techniques—steam distillation (SD), hydrodistillation (HD), and microwave-assisted distillation (MV). The results demonstrated that the extraction method significantly influences both the chemical profile and the antioxidant, antidiabetic, and neuroprotective activities of the oil. Overall, steam distillation (SD) exhibited the highest antioxidant and neuroprotective activity.
¿Qué es el Citrus aurantium y por qué interesa el aceite de sus hojas?
Citrus aurantium L., commonly known as bitter orange or sour orange, is a citrus species whose leaf essential oil—known as petitgrain—often receives less attention than the oil extracted from its flowers (neroli) or fruit peel, despite having a closely related chemical composition. A research team specifically investigated this leaf essential oil to answer a practical question: does the distillation method influence its quality and functional properties? According to their findings, the answer is yes—and to a significant extent.
The Three Distillation Methods Compared
The study extracted the essential oil using three different techniques and analyzed each sample through gas chromatography (GC/FID and GC/MS). A total of 35 volatile compounds were identified and quantified. The most striking finding was that the chemical profile changed significantly depending on the extraction method:
| Characteristic | Steam Distillation (SD) | Hydrodistillation (HD) | Microwave-Assisted Distillation (MV) |
|---|---|---|---|
| Major Compound | Linalyl acetate (64.08%) | Linalyl acetate (57.13%) | Eucalyptol (69.92%) |
| Linalool | 24,04 % | 23,69 % | 0,85 % |
| α-Terpineol | 1,63 % | 5,14 % | 7,82 % |
| α-Terpinyl Acetate | — | — | 9,86 % |
| Predominant Class | Monoterpenes | Monoterpenes | Monoterpenes |
In the steam-distilled (SD) and hydrodistilled (HD) samples, the essential oil is dominated by linalyl acetate and linalool, the two compounds most characteristic of Petitgrain’s aroma profile. In contrast, microwave-assisted distillation (MV) produces an oil with a completely different chemical composition, dominated by eucalyptol (nearly 70%), demonstrating how the extraction technique can dramatically reshape the final composition of the essential oil.
Figure 1. Bar chart showing the main classes of compounds identified in the three extraction methods used for Citrus aurantium essential oil.
Chemical Composition: Monoterpenes and Sesquiterpenes
Of the 35 compounds identified, monoterpenes were the most abundant class in all three samples, followed by sesquiterpenes. In addition to the compounds already mentioned, notable constituents included α-pinene, β-pinene, β-myrcene, terpinen-4-ol, geranyl acetate, and caryophyllene.
This richness in oxygenated terpenes forms the basis of the functional properties evaluated in the study. The consistency of this chemical profile depends not only on the extraction method but also on the quality and origin of the raw material. At Biottonia Essences, we ensure this consistency through comprehensive traceability from field to batch.
Properties and Biological Activity
The research team subjected the three essential oil samples to a series of in vitro assays.
Antioxidant Activity
Antioxidant capacity was evaluated using six different methods (DPPH, ABTS, CUPRAC, FRAP, PBD, and MCA). The steam-distilled sample (SD) exhibited the highest antioxidant activity, with the following results: FRAP 200.43 mg TE/g, CUPRAC 138.69 mg TE/g, ABTS 129.49 mg TE/g, and DPPH 51.67 mg TE/g. These values were clearly higher than those obtained for the other two extraction techniques across these assays.
Neuroprotective Potential (Related to Alzheimer’s Disease)
The study assessed the inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), enzymes associated with cognitive decline. Once again, the steam-distilled oil (SD) showed the strongest activity, with inhibition values of 3.73 mg GALAE/g against BChE and 2.06 mg GALAE/g against AChE.
Antidiabetic Activity
The inhibition of α-amylase and α-glucosidase, two enzymes involved in carbohydrate metabolism, was also evaluated. In this case, the results were more balanced among the extraction methods. The SD sample showed the highest α-amylase inhibition (0.32), while the microwave-assisted sample (MV) achieved the strongest α-glucosidase inhibition (2.73 mmol ACAE/g), followed by HD (2.53) and SD (2.46).
|
Best-Performing Method | Value | |
|---|---|---|---|
| Antioxidant (FRAP) | Steam Distillation (SD) | 200,43 mg TE/g | |
| Neuroprotective (BChE) | Steam Distillation (SD) | 3,73 mg GALAE/g | |
| Neuroprotective (AChE) | Steam Distillation (SD) | 2,06 mg GALAE/g | |
| Antidiabetic (α-Amylase) | Steam Distillation (SD) | 0,32 | |
| Antidiabetic (α-Glucosidase) | Microwave-Assisted Distillation (MV) | 2,73 mmol ACAE/g |
Potential Applications
The authors conclude that bitter orange essential oil may serve as a promising source of compounds with antioxidant, antidiabetic, and neuroprotective activity, offering potential for the development of future pharmacological applications. In addition, its traditional and emerging uses in wellness, aromatherapy, and advanced cosmetic formulations continue to grow, particularly due to its high content of linalool and linalyl acetate, two highly valued aromatic compounds.
You can explore our range of essential oils to discover the options available for product development and formulation projects.
At Biottonia Essences, we closely follow scientific advances that highlight the remarkable potential of essential oils and their future applications across multiple industries.
Frequently Asked Questions (FAQ)
What Is Bitter Orange Leaf Essential Oil Used For?
According to the study, it exhibits antioxidant, antidiabetic (through the inhibition of α-amylase and α-glucosidase), and neuroprotective activity (through the inhibition of the cholinesterase enzymes AChE and BChE), in addition to its well-established applications in aromatherapy and cosmetic formulations.
Which Distillation Method Is Best?
It depends on the intended application. Steam distillation (SD) delivered the highest antioxidant and neuroprotective activity, while microwave-assisted distillation (MV) showed superior α-glucosidase inhibition. The extraction method also has a significant impact on the oil’s final aromatic and chemical profile.
What Is the Main Compound in the Essential Oil?
In the steam-distilled and hydrodistilled samples, the main compound was linalyl acetate (64.08% and 57.13%, respectively). In the microwave-assisted distillation sample, the predominant compound was eucalyptol (69.92%).
Is It the Same as Neroli?
No. Neroli essential oil is obtained from the flowers of the bitter orange tree, whereas this essential oil is extracted from the leaves (Petitgrain), although its chemical composition shares similarities with both the flower and peel oils.
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Source: Elhawary EA, Nilofar N, Zengin G, Eldahshan OA. Variation of the essential oil components of Citrus aurantium leaves upon using different distillation techniques and evaluation of their antioxidant, antidiabetic, and neuroprotective effect against Alzheimer’s disease. BMC Complement Med Ther. 2024;24(1):73. https://pubmed.ncbi.nlm.nih.gov/38308284/