This week we look at Part II of this series, which discusses general aspects of essential oils. The authors of the review note that most dermatologists have limited knowledge regarding essential oils and would benefit from learning what they are, their application, and factors influencing their composition.
In answer to the question, “what is an essential oil,” the authors quote the International Organization for Standardization (ISO) as:
. . . a product obtained from a natural raw material of plant origin, by steam distillation (which includes hydrodistillation), by mechanical processes from the pericarp (peel) of citrus fruits or by dry distillation after separation of the aqueous phase—if any—by physical properties.1
This review study explains the many uses for essential oils:
- Flavor Industry: flavors for the food industry
- Food Industry: soft drinks, foods, alcoholic beverages, spices, herbs, tea, food preservation
- Fragrance Industry: perfumes, fragrances for other products
- Cosmetic Industry
- Household Products: detergents, softeners, room scents, candles, incense
- Tobacco Industry: cigarettes
- Pharmaceutical Industry: masking agent
- Animal food2
Essential Oil Adulteration
Photo courtesy: chemistry.tutorvista.com
The authors write that essential oils sold on the Internet “often bear labels as ‘pure,’ ‘natural,’ or ‘100% natural.’ Such labeling does not guarantee that the oils are of good quality. . . Poor or lesser-quality of essential oils can have various causes, including adulteration, contamination, inadequate oil production and aging.”3
The demand for essential oils is so high that our study mentions that adulteration can derive from “making more profit, demands of clients of the essential oil industry (who want cheaper oil), or to ensure sufficient supply of oils to clients, for example in the case of a bad harvest.”4
The surprise was to learn that a very close cousin of ylang ylang essential oil, called cananga oil, is far cheaper than the fragrant ylang ylang oil. Both are of the botanical family Annonaceae, and both carry the same botanical name with the difference in the variety. Ylang ylang essential oil is named Cananga odorata var. genuine, while cananga essential oil is known as Cananga odorata var. macrophylla.
Organoleptic methods are crucial for determining if the oil is true ylang ylang. A “nose” is one who can detect essential oil fragrance molecules in traces or even a few parts per million. Ylang ylang has a much more floral aroma than cananga oil, and any adulteration is easily detected.
One final note from this study emphasizes the skill of the distiller. The study states:
Especially in developing countries, the production plants are not always equipped to control parameters that guarantee optimal distillation. Perfect biomass [the raw plant material], which is distilled incorrectly, for example, too much steam, too high temperatures, or a badly functioning cooling unit, will inevitably lead to lower-quality oils.5
We are grateful to the authors, who hail from the Netherlands and Germany, for enlightening readers of this dermatology journal. Their review study has been informative for us as well.