What Is Absolute Oil?
Absolute oil is a highly concentrated aromatic extract derived from delicate flowers or aromatic plants. Unlike essential oils, which are typically obtained through steam distillation or cold pressing, absolute oils are extracted using solvent extraction or enfleurage. This method preserves the full complexity of the plant’s fragrance and chemical composition, making absolutes highly sought after in high-end perfumes, cosmetics, and aromatherapy. Popular examples include jasmine absolute, rose absolute, and tuberose absolute.
How to Extract High-Quality Absolute Oil? Two Main Methods
Currently, there are two primary methods for extracting absolute oil: solvent extraction and enfleurage.
1. Solvent Extraction – The Mainstream Method for Absolute Oil
1.1 Principle
Solvent extraction involves using organic solvents like hexane or ethanol to dissolve the aromatic compounds from plant material. The solvent is then evaporated to obtain the absolute oil.
1.2 Step-by-Step Process
- Plant Soaking: Flowers or aromatic plants are submerged in a solvent (e.g., hexane) to dissolve the fragrance compounds, waxes, and pigments.
- Solvent Filtration: The mixture is filtered to remove plant residues, leaving behind a fragrant solution.
- Solvent Evaporation: Low-temperature evaporation removes most of the hexane, producing a waxy substance known as a concrete, which contains aromatic compounds.
- Ethanol Purification: Ethanol dissolves the concrete, extracting the aromatic components and leaving waxes behind.
- Final Evaporation: The ethanol is evaporated, resulting in highly concentrated absolute oil.
1.3 Suitable Plants
- Jasmine Absolute – Intensely fragrant, widely used in high-end perfumes.
- Rose Absolute – Richer aroma compared to steam-distilled rose essential oil, perfect for skincare and perfumes.
- Tuberose Absolute – A key ingredient in luxury perfumes with a sweet floral scent.
- Gardenia Absolute – Exotic floral fragrance, ideal for premium perfume formulations.
1.4 Pros & Cons
- ✅ Retains complete aromatic molecules, capturing more floral essence than steam distillation.
- ✅ Suitable for delicate flowers like jasmine and tuberose, which cannot withstand high temperatures.
- ❌ May contain trace solvent residues, making it unsuitable for food or medicinal applications.
- ❌ Higher production costs make absolute oils more expensive than regular essential oils.
2. Enfleurage – A Traditional and Luxurious Extraction Method
2.1 Principle
Enfleurage is an ancient technique, particularly suited for delicate flowers like tuberose and jasmine. It relies on the absorption properties of animal fat or vegetable oils to capture aromatic molecules from flowers, followed by ethanol extraction to obtain the absolute oil.
2.2 Step-by-Step Process
- Prepare the Fat Base: Animal fat or plant oil is spread onto glass plates.
- Flower Placement: Fresh flowers are evenly laid over the fat layer, allowing their aromatic compounds to be absorbed.
- Flower Replacement: Flowers are replaced every 24-48 hours to continuously absorb fragrance, repeated over several days or weeks.
- Extracting Aromatic Compounds: Ethanol is used to dissolve the absorbed fragrance from the fat.
- Alcohol Evaporation: Low-temperature evaporation removes ethanol, yielding high-purity absolute oil.
2.3 Suitable Plants
- Tuberose Absolute – Enfleurage perfectly preserves its sweet and sensual aroma.
- Jasmine Absolute – Ideal for luxury perfumes and aromatherapy.
2.4 Pros & Cons
- ✅ Preserves the purest floral scent, more natural than solvent extraction.
- ✅ No chemical solvent residues, making it ideal for high-end fragrance products.
- ❌ Lengthy production process, often taking weeks or months.
- ❌ High production costs make enfleurage-derived absolutes among the most expensive fragrances.
What Is Essential Oil?
1. Definition of Essential Oil
Essential oil is a highly concentrated, volatile aromatic compound extracted from flowers, leaves, stems, roots, peels, or resins of plants. It contains active components such as terpenes, alcohols, aldehydes, and phenols, which provide unique fragrances and therapeutic properties.
Essential oils are widely used in aromatherapy, skincare, medicine, food, and cleaning products. Popular varieties include lavender, tea tree, lemon, and rose essential oils.
2. How to Extract High-Quality Essential Oil?
| Extraction Method | Principle | Suitable Plants | Advantages | Disadvantages |
|---|---|---|---|---|
| Steam Distillation | Steam passes through plant material, carrying essential oil, then condenses for separation | Most plants like lavender, tea tree | Well-established, cost-effective | High temperatures may degrade some active compounds |
| Cold Pressing | Mechanically presses peels to release essential oils | Citrus fruits like lemon, orange | Solvent-free, retains full aroma | Prone to oxidation, shorter shelf life |
| Supercritical CO₂ Extraction | Uses CO₂ in a supercritical state to dissolve essential oils, then releases them under reduced pressure | Premium oils like rose, chamomile | Low-temperature, solvent-free, retains active compounds | Expensive equipment, complex process |
| Solvent Extraction | Organic solvents dissolve essential oils, then solvents are evaporated | Flowers like jasmine, rose | Retains full fragrance, ideal for luxury perfumes | May leave solvent residues, unsuitable for food or medicine |
Absolute Oil vs. Essential Oil: Key Differences
| Feature | Absolute Oil | Essential Oil |
|---|---|---|
| Extraction Method | Solvent extraction / Enfleurage | Steam distillation / Cold pressing / Supercritical CO₂ extraction |
| Purity | Higher concentration, richer fragrance | Relatively pure but may lose some components due to heat |
| Suitable Plants | Jasmine, rose, tuberose, gardenia | Lavender, tea tree, citrus oils |
| Solvent Residue | Possible trace amounts | No chemical solvent residue |
| Applications | Luxury perfumes, cosmetics, aromatherapy | Daily skincare, medicine, food flavors |
| Price | Expensive, limited supply | More affordable, widely available |
Absolute Oil, Essential Oil, and Supercritical CO₂ Extraction
1. How Does Supercritical CO₂ Extraction Impact Essential and Absolute Oils?
1.1 Impact on Essential Oils
Supercritical CO2 extraction is a solvent-free, efficient, and eco-friendly method. Compared to traditional steam distillation, it offers the following benefits:
- Low-Temperature Extraction: Preserves heat-sensitive compounds like terpenes and phenols, enhancing essential oil potency and aroma.
- Selective Extraction: Adjustable temperature and pressure allow targeted extraction of specific compounds, producing high-purity essential oils.
- Solvent-Free: Unlike solvent extraction (used for absolute oils), CO2 extraction leaves no chemical residues, making it ideal for food and medical-grade essential oils.
Examples:
- Chamomile Essential Oil – CO2 extraction preserves more chamazulene, boosting its anti-inflammatory properties.
- Rose Essential Oil – Retains a fuller fragrance with a higher concentration of esters than steam-distilled rose oil.
1.2 Impact on Absolute Oils
Traditional absolute oils are extracted using solvents like hexane and ethanol. While effective, these methods may leave chemical residues, making them unsuitable for medicinal or food use.
Supercritical CO2 extraction offers a solvent-free alternative for producing absolute-like oils with superior purity and safety, making them suitable for organic perfumes and high-end skincare products.
2. Future of Absolute and Essential Oils with Supercritical CO2 Extraction
With the growing demand for organic and chemical-free products, supercritical CO2 extraction is becoming the preferred method for high-quality essential and absolute oils. Its high purity, eco-friendliness, and ability to retain delicate fragrances make it the future of the essential oil industry.