Dried jasmine flowers

Jasmine Fragrance oil

The most cultivated and commercialized species of jasmin, include Jasminum officinale (Common Jasmine), Jasminum sambac (Indian jasmine) originates from India and Arab, and then cultivates wildly in Iran, Egypt, or China, and Jasminum grandiflorum (Spanish Jasmine) for both the domestic and industrial uses, such as the perfume industry because of the characteristic fragrance of their flowers. There are two types of flowering: winter jasmine with yellow flowers and summer jasmine with white or pink flowers.
During Spring, jasmine’s flowers lend a floral scent that is rich and sweet, almost honey-like scent. Indeed, 90%-95% of its organic chemical components are volatiles. However, depending on the jasmine specie, the smell can be different: Florida jasmine, for example, has a powerful tropical vibe. Chinese Jasmine tends to have notes of spice-cloves or cinnamon. Indian Jasmine may come across as fruity or even as citrusy. Most Jasmine scents today come from Jasminum officinale flowers because they provide deep and sweet smells. For higher aroma/smell properties and for preservation of the essence of the volatiles, jasmine flowers are harvested in the early morning.
In addition to the perfume industry, Jasmine is usually used in food industry and aromatherapy for its calming, uplifting effects on the mind and body.

The purpose of this study is to analyze the mixture of molecules and identify the natural and synthetic ones that allow to recreate the smell of jasmine flowers.

The Fragrance Oil

Dried jasmine flowers

Jasmine flowers smell great, but they don't make essential oils like some other flowers do. That's because they don't have many oil glands in their flowers, so there's not much oil. Also, the specific chemicals needed for making lots of essential oil might not be in jasmine. Even if there's a bit of oil, getting a lot of it out is hard. So, perfumers often use different ways, like synthetic fragrances or other natural floral scents, to get the lilac smell into their products. Even with these challenges, people still love the smell of jasmine, and it keeps inspiring the perfume world.

Analysis

spectrum

Once the fragrance was diluted at a concentration of 0,5µg/mL in the non polar solvant, it was analyzed by GC/MS.

GC-MS analysis is useful to identify and quantify the components of Fragrance oil with the following parameters:

•Oven Temperature: 40°C - 300°C
•Rate: 15°C/min
•Inlet Temperature: 250°C
•Column Flow:1,3 mL/min
table

By examinating GC/MS results, it appears the fragrance is a mixture of 8 compounds,  from natural and synthetized origin. The odorous properties of natural ones allow to recreate the scent of the fragrance as the company describes it on the website: “top note is a floral bouquet of lily of the valley, ozone and floral apple with a touch of grape, the middle note is the main one with jasmine and the fragrance comes to a well-rounded finish with woody and musk note ate the base ».

diagram

Among these compounds, linalyl acetate and linalool; from the lavender essential oil, 2-hexyl cinnamaldehyde and D limonene; from the jasmine absolute, contribute to the floral and fruity top note.

Other molecules of the jasmine absolute, which are benzyl acetate and methyl dihydrojasmonate, bring the jasmine middle note.

Neither molecule clearly contributes to the musky and woody base note. However, because the GC/MS system can’t distinguish chirality from molecules, I hypothized that fragrance contains a mixture of the 2 enantiomeric form of limonene. In this case, L-limonene which has a piney scent would create the woody base note.

Then there are synthetic molecules such as DEHA and benzyl alcohol which don’t contribute in the smell of the product but only in the formulation. They are used to improve the durability of the fragrance oil by stabilizing it over time. Additionally, they can serve as a solvent, helping to dissolve and distribute compounds.

Comparison with the website data

list

According to the commercial ingredients list on the safety data sheet of the jasmine fragrance, the commercial product contains 8 natural or synthetic ingredients, used for their properties, with a majority of Linalyl acetate (7-15%) and Octanal, 2-(phenylmethylene)- (5-10%). The linalyl acetate, 2-hexylcinnamaldehyde, linalool and benzyl alcohol were identified by GC/MS with valid concentrations within the official concentration range. However, fragrance contains principally 50.61% of DEHA and 10.50% of methyl dihydrojasmonate that are note referenced into the list of ingredients.

Let's take a closer look at these molecules.

molecule
  • Methyl Dihydrojasmonate

Methyl Dihydrojasmonate is a pale yellowish or almost colorless oily liquid with a warm, sweet-floral, jasmine-like and fruity odor. It is produced naturally by plants such as jasmine as a defense system, but its synthetic version is more commonly used to guarantee consistent quality and help preserve the planet's natural resources.  Present in many consumer products as a fragrant compound, this ingredient is also used as the basis for many other floral fragrances. Indeed, Methyl dihydrojasmonate is an additive capable of binding other more volatile components. It is therefore widely used on an industrial scale to improve the longevity and diffusion of fragrances. 

Finally, methyl dihydrojasmonate has a dual function in the fragrance. While it’s useful for recreating the scent of jasmine, it can be considered as an additive, a secondary compound that is not necessarily listed on the ingredient list.

molecule
  • DEHA

DEHA is an industrial chemical that helps to improve the flexibility and durability of the fragrance oil, ensuring that it remains stable over time. Additionally, this additive can serve as a solvent, helping to dissolve and distribute the fragrance compounds evenly throughout the oil. DEHA is also a plasticizing agent to which we can be exposed using consumer products such as PVC packaging, cosmetics or via industrial releases into the environment during production operations. Nevertheless, it is a product recognized as dangerous by international health and environmental bodies.

Because the fragrance oil comes from the Candian market, let's take a look at the Canadian health service. From December 2006 to June 2010, scientific critically studies evaluated the risks of DEHA. This became a major challenge published in the Canada Gazette on 26 September 2009, and numerous studies described on the Government of Canada website were carried out. It emerged that this chemical could migrate from food packaging into food, that high levels of exposure can cause liver, reproductive and developmental effects and that it is a persistent environmental pollutant. DEHA has therefore been shown to be carcinogenic and harmful to the environment and biological diversity. Control of this substance has been deemed to be a high priority, and it is being closely monitored through the implementation of risk management measures. Some even believe that it should be included on Health Canada's Cosmetic Ingredient Hotlist. 

With this in mind, we can hypothized that the company does not list this toxic chemical additive to appear more ‘natural’ in order to maximize consumer confidence and protect the formulation receip from competing compagnies. Indeed DEHA is not an active ingredient for odor, it is quite likely that regulations will exempt secondary additives from the list of ingredients.

Headspace Analysis

spme

To complete the study and see if the fragrance can be toxic by inhalation, the headspace of the heated fragrance oil was analyzed by using the combination of the SPME extraction method with the GC/MS analysis system.

In a vial closed with parafilm and placed on a hot plate the fragrance is heated. For 10min the headspace is taken with an SPME needle. The analysis program was almost the same that the one for the fragrance oil analysis except for the temperature of the inlet, which has been lowered to 200°C to detect and not burn all the most volatile and delicate molecules.

spectrum

According to the results, the 5 most volatile ingredients of the fragrance oil, which are D-Limonene, benzyl alcohol, linalool, benzyl acetate and linalyl acetate, constitute the headspace of the heated fragrance. Their concentration increases with the heating temperature.

These results are reassuring because they highlight that everyday odorous product, made from this perfume oil, diffuse a non-toxic floral odor containing natural molecules. Indeed, heavy molecules with complex structure such as DEHA remains in solution, so it is not ingested by inhalation.

Conclusion

To conclude, we can see that the perfect balance of each chemical component allows to recreate the smell of jasmine flowers. The mix of natural and synthetic molecules  brings back memories of hot summer days when the scent of flowers wafts across the Mediterranean coast.

Natural compounds are predominant because they made up the fragrance thanks to their smell properties. Each one is not necessarily added individually: we can suppose that linalool and linalyl acetate provide from the lavender essential oil. Also D-limonene, benzyl acetate, 2-hexyl cinnamaldehyde and methyl dihydrojasmonate are naturally present in the jasmine absolute. 

Moreover, synthetic molecules allow to intensify the smell and stabilize the chemical composition over time to create a product with multiple uses.

According to our research, fragrance is a safe product. However, care must be taken when using this chemical product as it can cause irritation.

Emmy Bousquet

emmy

My name is Emmy, I am 19 and I’m studying chemistry at the IUT of Montpellier in the south of France. Thanks to my institution I have the opportunity to carry out my internship at the University of Ottawa as a Visitor Research Student to take part in the Sharon Curtis Hydrosol project.

It’s a wonderful experience to develop chemical knowledge about odorant products, to gain more practical experience in analytical chemistry and to work in a multicultural environment with Sharon Curtis and some grad students in Paul Mayer’s lab.

All the knowledge I've gained is very fascinating and enriching in terms of realizing my dream of a career in perfumery.

I'm glad to have worked on Sharon's new research project around fragrance oils. My study focused on the smell of jasmine that is a signature of the hot Summer day on the Mediterranean coast where I grew up !