Essential oils have a complex composition. One single oil may contain hundreds of individual constituents from a variety of chemical families. Although this complexity may seem overwhelming to all but the most advanced scientist, it is actually a vital part of the beneficial value of essential oils. Every different class of constituents offers unique biochemical properties that allow them to react in a certain way. Together, a variety of constituents work together as a complete synergistic unit to maximize the functionality of the oil and in turn, enhance its applicable beneficial properties. In plants, this allows the plant to be dynamic and adaptive in its environment by conferring certain protective and reproductive benefits. In humans, this allows essential oils to have endless applications to health and wellness. A single essential oil may have many functions because of their complex chemical profiles. For example, lemon oil is renowned for its powerful purifying properties and is useful as a cleaning agent. On the other hand, it has also been demonstrated to have powerfully uplifting effects on mood.
Previously mentioned in Module 3, the chemical profile of an essential oil is a crucial determinant of the overall quality. Certified Pure Tested Grade™ essential oils should always have certain ratios of the same core constituents, as these major constituents are largely what determine how the oil will interact in the body. Because essential oils are pure botanical extracts, the ratio of constituents will fluctuate slightly depending on the geographic location, weather conditions, soil conditions, insect presence, precipitation, temperature, distillation conditions, etc. Quality control tests should be used to monitor the chemical profile of each batch of oil and determine if it fits within the proper ranges that will result in beneficial health effects.
Take peppermint for example. Peppermint is distilled from the whole peppermint plant and is sourced indigenously from the northwestern United States. The ratio of the constituents menthol to menthone is used as a marker for high quality peppermint oil. Certified Pure Tested Grade™ peppermint oil should always have a significantly higher proportion of menthol because menthol has been shown to improve the beneficial value of peppermint essential oil. One study tested the cleansing properties of peppermint essential oil from three different species. Peppermint from Mentha piperita was demonstrated to have the highest cleansing properties, which was attributed to its high amount of menthol and low amounts of menthone. Conversely, the Mentha aquatica species was shown to have significantly lower cleansing properties and also had a lower amount of menthol and a higher amount of menthone. (Mimica-Dukić N, Et Al. 2003)