You will not be hard pressed to find articles on the Internet claiming that essential oils are nutrient rich substances. However, when we look at the basics of chemistry and the process of essential oil extraction, we quickly see that this is not possible. Let’s cover some of the main key points in the argument.
- Basics of Solubility
Vitamins are either fat soluble, such as vitamins A, D, E and K, or water soluble, like vitamins B’s and C.
The solubility of vitamins is different than that of essential oils. No essential oil is soluble in water. All essential oils are lipophilic (fat loving), also called non-polar substances. In looking specifically at Vitamin C, it is hydrophilic (water loving), and very polar in nature. As a general rule, polar substances will dissolve in polar solvents and non-polar substances will dissolve in non-polar solvents.
- The Volatility of Essential Oils VS All Water-Soluble Vitamins
Next let’s talk about volatility. All essential oils are volatile. What does this mean? Volatility refers to the ease with which a substance will evaporate, or at which rate a liquid will turn into a vapor. This is the #1 reason why we need to keep the caps on our bottles tight, to eliminate evaporation and more importantly oxidation of our precious essential oils. Though essential oils do not require heat to be volatile (evaporate), they will do so much quicker when at higher temperatures. Air, as well as heat and light are not their friend.
All water-soluble vitamins are polar in nature and are extremely volatile.
- Steam Distillation VS Cold Pressed Extraction
The most common method of the extraction of essential oils from a plant is using heat in a process called steam distillation. The heat sits right around 100° C/212° F. The plant material is placed in a still; the steam of boiled water passes through the plant material and is then cooled to collect the essential oil. This essentially separates the volatiles from the non-volatiles. The higher the temperature, the more volatiles will be lost, so temperature needs to be very specific.
There has been an argument that vitamin C will crossover in the essential oil that has been cold-pressed. Cold-pressed essential oil is another extraction method for citrus fruits. Extraction or mechanical pressing is quite different than steam distillation. This method uses no heat. Machines are used to pierce the fruits rind and they are then pressed to extract the precious oils. This method “may” contain “minute” amounts of vitamin C. It will be negligible, but nothing to write home about. Be sure to continue to obtain your vitamin C from the real fruit.
- Water-Soluble Degradation
The various B Vitamin’s degrade when they get much higher than room temperature. Vitamins B1, B6, and B12 are the most susceptible to degradation, therefore will not be extracted with the essential oil (1).
Vitamin C degrades at 70° C, which is lower than that of the steam distillation process and therefore will also not be extracted with the essential oil (2).
As you can see, most if not all of water-soluble vitamins will either be destroyed or left in the water through the steam distillation process.
- Fat-Soluble Vitamins
Fat-Soluble vitamins such as A, D, E, and K, are lipophilic in nature (lipids), and non-volatile. There are two key points here: 1-the end product of steam distillation only contains volatile material, and 2- the degradation of the lipids due to the heat involved.
The heat of the steam distillation process we now know sits right around 100° C/212° F. The steam distillation process from beginning to end varies per the plant material in the still as well as the size and type of still, but heat over an extended period of time will degrade fat-soluble vitamins.
Consider this: we are told to store vitamins in a cool dark place, away from heat. Do you still think they can survive the heat of steam distillation?
Minerals such as chromium, magnesium, iron, zinc, and so on are ionic in nature. Ionic substances are very polar in nature, but are not technically polar molecules (3).
Minerals are water-soluble. Like water-soluble vitamins, minerals will not move over through the steam distillation process, but will rather be left in the water.
Have I lost you yet? Let’s Quickly Review
*Water-soluble vitamins like B’s and C will degrade under the heat of steam distillation.
*You may get minute amounts of vitamin C through the cold-pressed method, but very little.
*All water-soluble vitamins are completely insoluble in non-polar solvents such as essential oils.
*Fat-soluble vitamins will also degrade under the heat of steam distillation. They are also non-volatiles that will not make it through the steam distillation process, but will rather be left in the water.
*Minerals are ionic (polar in nature), and water-soluble. Minerals will not make it through the steam distillation process, but will rather be left in the water.
*If there is one point to remember in all of this: The process of steam distillation removes all non-volatile foreign matter, mineral as well as organic, and leaves behind only volatile matter.
We can now see that due the basics of chemistry and the heat of the distillation process that essential oils cannot possibly contain any nutrients. No water-soluble vitamins, fat-soluble vitamins, or minerals. What we do know is that essential oils have great capability, great energy, and great promise.
(1) Fortification basics, stability. Retrieved from https://www.dsm.com/content/dam/dsm/nip/en_US/documents/stability.pdf
(2) Rahmawati, S., Bundjali, B. Kinetics of the oxidation of vitamin c. Retrieved from http://www.researchgate.net/publication/228484005_KINETICS_OF_THE_OXIDATION_OF_VITAMIN_C
(3) Introduction to ionic compounds. Retrieved from http://chemistry.elmhurst.edu/vchembook/143Aioniccpds.html
Leslie Moldenauer, CHNC, HHP, Certified Aromatherapist, has been studying natural living and holistic wellness for over 10 years. Leslie is a trusted resource that covers essential oil safety and encompasses all that natural living has to offer. She is passionate about providing education and tools to help others make decisions regarding safety above all things when utilizing aromatherapy in the home.