What are Essential Oils?

Question 1

What are essential oils?

Answer 1

• Essential oils are highly concentrated, volatile, aromatic essences found in many plants.
• The role they play in each plant is varied and not entirely understood but includes attracting beneficial insects and repelling unwanted ones and protecting the plant from harmful bacteria.
• Essential oils are stored in specialized cells or reservoirs in the plant. Depending on the plant these oils can be found in the root, leaf, flowers, fruit or seed

Question 2

Processes of Obtaining Essential Oils

Answer 2

• To obtain the oil it must be released from storage pockets in the plant.
  
  • Take a fresh peppermint leaf and handling it carefully to avoid bruising, smell it. Little or no fragrance will be detected. Now rub the leaf between your fingers to break the cell walls and smell the leaf again – the strong, crisp scent of peppermint oil is now released.
• Through distillation (primary method), expression, absolutes, and CO₂ extraction

Question 3

Where do most essential oils come from?

Answer 3

• Essential oils come from all over the world. Most essential oils are distilled on the farm or near where the plant is grown. Therefore, essential oils tend to come from the regions of the world where the plants are cultivated. Besides North America, many oils come from Europe and Southeast Asia.

Question 4

Do many oils come from the United States?

Answer 4

• There are some essential oils such as peppermint, spearmint, Texas cedarwood, dill (used in dill pickle production), wintergreen and the citrus oils that are commercially produced in the U.S. However, most are produced in other parts of the world, often in limited areas that provide the particular requirements of the plant from which they are made.

Question 5

Essential Oil Distillation

Answer 5

• The primary method of producing essential oils is through steam distillation.
• thought to have originated in Persia somewhere around the 10th century AD
• Water is heated to boiling and its steam passes through fresh plant material stacked on a rack above the boiling water. This causes the cell walls of the plant material to break down and release the essential oil. The water and essential oil vapor then passes through a cooler that condenses the steam and the oil into a liquid. The liquid is collected and the oil is separated from the water.

Question 6

What is a Hydrosol?

Answer 6

• After steam or water distillation of an essential oil, the leftover water from the distillation is called a hydrosol.
• Hydrosols are mostly water with the water soluble components of the plant not found in the essential oil. They usually contain a very tiny bit of essential oil —at least enough to give the hydrosol the faint aroma of the oil.
• They are considered great additions to skin toners and sprays, masks and lotions where they are valued for their astringent, soothing and rejuvenating qualities. Because they are almost all water, they are can be used directly on the skin without dilution.

Question 7

What does the “otto” mean in Rose Otto?

Answer 7

• Rose otto is the steam or water distilled essential oil of the fresh petals of the damask rose (Rosa damascena) and is considered the finest rose oil in the world (and also the most expensive).
• Also known as attar of rose, rose otto has an intensely warm, rich, deeply rosy scent.
• The term otto is derived from Ottoman.
  
  • It was during the rule of the Ottoman Empire that rose oil production was spread to the many Ottoman provinces, including—in the mid-fifteenth century—certain areas of what is now Bulgaria. These areas were ideally suited to rose flower production and soon became the major producer of rose otto—which they continued to be until after World War II. Today Turkey provides about 75% of the world’s production of rose otto.

Question 8

Essential Oil Expression

Answer 8

• a mechanical method of pressing citrus peels such as lime, lemon, orange and grapefruit to remove the essential oils.
• Expressed oils contain the essential oils along with a tiny amount of part of the fruit such as colorants and waxes from the fruit.
• Although an essential oil without any of these additional components can be created through distillations, citrus oils are especially fragile and the resulting oil does not have the same “fresh fruit” aroma and quality of the expressed oil.

Question 9

Essential Oil Absolutes

Answer 9

• Usually made today by first using a solvent to extract the essential oil from the plant part (concrete), then washing with alcohol to separate the essential oil from the solvent.
• This method is used when the heat of distillation would damage delicate oils or when the quantity of oil in the plant is so low that distillation would not be an effective method of extraction.
• They are produced by alcohol extraction, after which the alcohol is removed by vacuum distillation. Our GC testing shows that one to two percent alcohol may be left in an absolute.
• Examples of absolutes are rose, carnation, hyacinth, violet and jasmine

Question 10

Essential Oil CO₂ Extraction

Answer 10

• a relatively new, but efficient, method that uses CO₂ under high pressure to remove the essential oils.
• Because of the low temperatures used, the aromas of the oils produced under this method are exceptionally true to those of the plant. However, the high cost of the equipment and complexity of the process makes the cost of these oils prohibitive in most cases.

Question 11

Essential Oil Chemistry

Answer 11

• Variation in the amount of each chemical constituent can occur in an essential oil because of variations in climate, soil, seasonal growing conditions, harvesting methods and even handling techniques.
• For some plants, however, a difference in the chemical composition occurs due to differences in genetics. The result is a chemotype of that plant.
  
  • A chemotype is usually identified by a constituent that is present naturally in a relatively high amount and, because of its higher concentration, affects how the essential oil is used. For example, thyme (T. vulgaris) has many chemotypes. The thymol chemotype is strongly antibacterial, but is irritating to the skin and mucous membranes because of the higher amount of thymol present. The milder geraniol chemotype, on the other hand, also has antibacterial properties, but does not cause the irritation of the thymol thyme.
• Essential oils often share the same chemical constituents. Knowing which constituents and at what levels they’re present in the oil can give clues to the oil’s properties as well as its hazards. For example, essential oils that contain eucalyptol (such as eucalyptus and tea tree) are useful for relieving respiratory tract congestion. And oils with even low levels of thujone—a neurotoxin—should be used with caution (sage, yarrow), and those with higher amounts (mugwort, wormwood) avoided entirely.