Ebooks doTERRA Essential Oil Chemistry Handbook | Page 14

Part 1: The Basics of Essential Oil Chemistry easily separated from the water. Cold Press is a method that doesn’t involve heat. Cold press extraction is used exclusively with citrus fruits because it is a way of extracting oil from the outermost layer of the fruit’s peel. The fruit is passed across sharp rasping cylinders that abrade the surface of the peel to break open small essential oil-containing sacs. Water is then sprayed over the fruit to collect the essential oil. The resulting watery mixture is then filtered and centrifuged to separate the essential oil from the water. Solvent Extraction can be used on every type of plant material, but is most commonly used on flowers that are too fragile to endure the conditions required for steam distillation. The plant material is washed with a solvent to dissolve out the fragrant compounds. The resulting mixture is then filtered to remove the plant material, and then the solvent is removed using vacuum distillation. The yield of this process is a thick, waxy material called a “concrete.” The concrete is processed again in a similar fashion but with a different solvent. After another round of vacuum distillation to remove the second solvent, a pure mixture of only absolute remains. Common absolutes extracted by this method are Jasmine and Vanilla. 1.3 ESSENTIAL OILS ARE COMPLEX MIXTURES OF AROMATIC COMPOUNDS Essential oils are made of volatile aromatic compounds. Volatile aromatic compounds are small organic molecules that tend to change from the liquid state to the gas state at room temperature. These molecules are so incredibly small that a single drop of essential oil contains around 40,000,000,000,000,000,000 (40 million trillion) of them. The word “volatile” emphasizes their tendency to evaporate quickly at room temperature. This property is what makes them smell so potent. When you first open a bottle of essential oil, you instantly notice the aroma, and you can smell it even from a distance. The 4