Essential oils are popularly known for their use in soaps, perfumes, toilet products, detergents, alcoholic drinks, food products, and cosmetics. They are also used to promote relaxation and well-being in aromatherapy. The essential oils are obtained from aromatic plants. They are referred to as essential oils because they contain the ‘essence’ of their plant’s fragrance. Proper extraction from the plants is required to acquire the oils. Manufacturers use various extraction methods with the major physical and chemical processes being steam distillation, cold pressing, and solvent extraction.
Plant materials from which essential oils can be extracted include leaves, buds, flowers, fruits, barks, and roots. The steam distillation process makes use of steam to get the required plant compound. The process ensures the final product is organic and solvent-free. This method doesn’t require any other separation steps, with the single distillation process being enough.
The first step is to place the plant material, which is also known as the charge, in a still. Most times, the still is made out of stainless steel material. Introduce steam into the still where the plant is being held. Due to its volatile nature, exposure to steam will cause the essential oils to evaporate. The combination of the essential oil and steam rises to the top of the still and enters into a condenser.
The condenser is surrounded by cold water, which forces the steam/essential oil to change into liquid form. The liquid collects into a receiver, which is at the end of the condenser. The liquid, a combination of water and essential oil, forms a layer in the receiver. This is brought about by the fact that organic compounds are insoluble in water. Since organic compounds are lighter than water, it will settle at the top. The two are then separated by siphoning the essential oil. The recondensed steam/water is referred to as hydrolat, hydrosol, or plant water essence. The hydrosol can also be sold as a fragrant product such as Rosewater.
Unlike steam distillation, cold pressing does not utilize high temperatures. This is favorable because when some plants are subjected to high heat levels, the tiny molecules within the oils break down and degrade, ultimately minimizing the oil’s health benefits.
The cold pressing process is mainly done when extracting essential oils from citrus fruits such as tangerines, mandarine oranges, limes, and lemons. The extraction process is mechanical and can also be referred to as expression. Initially, the cold pressing process was done by hand and required the use of specialized sponges. The sponges were used to collect the oils, and once the sponges got saturated, they would get squeezed into a container. Cold pressing now is less labor-intensive than it was before.
The first step of the cold pressing process is to place the entire fruit in a spike filled container that causes the essential oil sacs to rupture. The oil will settle in the collection area of the container. A centrifuge is necessary to separate the oil, juice, and solids from the fruits. The layer of juice and oil is separated by siphoning, which leaves you with the essential oil. The essential oil can be used in its pure form, or other products can be added.
The cold pressing process is beneficial because it retains the natural properties (fragrance, purity, flavor) of the oil. The use of heat sources to extract oils generates a high quantity of the oil but compromises its quality.
The solvent extraction process is one of the most modern processes of extraction. It makes use of solvents such as ethanol and hexane. For extraction to take place, the plant material and the solvent are mixed. This extraction method is favorable for delicate plant parts such as flowers and plants that yield minimal amounts of essential oils. Other plants cannot take the distress and pressure of steam distillation and, therefore, use solvent extraction.
This method is more effective than other distillation processes as it produces a finer fragrance. Waxes and pigments, which are non-volatile plant materials, are extracted during the process and have to be removed by subjecting them to other processes.
The first step of the solvent extraction process involves exposing the flowers to a chemical solvent. By doing this, the hexane, ethanol, or preferred chemical solvent absorbs the essential oil. The mixture of the two liquids is known as an extract. The next step requires the separation of the solvent from the essential oil. The extract is placed in a vacuum, which is an environment with low pressure. This lowers the solvent’s boiling point, and you only need minimal heat to get rid of it. What is left behind is the extract that contains wax, essential oil, and other plant material. This combination is also referred to as concrete.
To retain the essential oil, add alcohol to the concrete. The subjection of the mixture to low temperatures will cause the wax to precipitate. Separate the residue by filtering and get rid of remaining alcohol through distillation.
Overall, the use of essential oils in different aspects of everyday life has increased. Each extraction process has its share of advantages and disadvantages. With steam distillation, you receive high-quality yield and high-quality oil, yet it is time-consuming. The previously used hand pressing was impractical as it took a lot of time to get the oils, but thanks to newly designed machines, the process has been made easier with cold pressing. The immiscibility of liquids and their solubility plays a significant role in the extraction process of essential oils.
At-Home Spa & Therapeutic Beauty Care Online Store
Escaping into the spa for an hour or two has many benefits, but it can also be expensive. Find budget-friendly items, therapeutic treatments that will keep you looking youthful healthy longer. Make this soul-soothing experience more affordable by browsing the MOMIJI aromatherapy collection.
- Scented Aromatherapy Candles 3pics Set$15.80
- Organic Herbal Bath Bags – 3 bags, 5 bags, 10bags$24.00 – $68.00
- Sandalwood Pure Essential Oil – 10ml, 30ml, 50ml, 500ml$15.84 – $143.84