IONONE ALPHA – floral, powdery and fruity note with hints of violet, dried plum and sweet root

A floral fragrance reminiscent of iris and violet, with a woody undertone. A sweet woody-floral aroma of violet and iris, tropical fruity, violet, and raspberry, which lends fragrances a hint of violet and berry. It is the most floral and the most "purple" of all ionones. When diluted, it releases notes of violet and iris.
Violet flower oil (Viola odorata L., Violaceae family) was one of the most expensive materials for perfumery until its production became economically unviable. Von Zoden reported that its price exceeded 80,000 German gold marks per kilogram due to the low concentration of essential oil in violet flowers.
Therefore, determining the odor structure of violet flowers was of great economic interest. However, the quantity of violet oil required for this work was also too expensive. Therefore, Timann and his colleague Paul Krüger used iris root oil (Iris pallida LAM.), which has a similar odor but is much cheaper, in their research on the principle of violet odor, hypothesizing that the odor of both oils was due to the same natural product. An incorrect elemental analysis of the extracted ionones led them to the conclusion that they could be produced by the condensation of citral and acetone, but these pseudo-ionones proved odorless. However, when they cleaned the reaction flask with sulfuric acid, they noticed a strong odor of violet flowers. They had accidentally discovered what they were originally looking for: the principle of violet odor. Only in 1972, a thorough analysis of violet flower oil with modern analytical instruments confirmed that its odor is actually due to the mixture of alpha-ionone and beta-ionone.
A recent analysis of the free space in viola flowers revealed 35.7% alpha-ionone, 21.1% beta-ionone, and 18.2% dihydro-beta-ionone, which together constitute 75% of the free space.
All three double-bonded ionone isomers (alpha, beta, and gamma) occur naturally as secondary metabolites of carotenoids, with gamma-ionone being the rarest.
Of the 1,250 scented flower species examined by Roman Kaiser up to 2002, beta-ionone was found in 16%, dihydro-beta-ionone in 11%, and alpha-ionone in 4% of all cases, illustrating the importance of ionones for natural floral scents, especially the beta isomers. In perfumery, alpha-ionone was initially more popular than beta-ionone, but in recent decades, the more intense beta-ionone (olfactory threshold 0.12 ng/l of air) has emerged as the preferred isomer in perfumery, reflecting a trend toward greater naturalness.
Ionones had a huge impact on perfumery immediately after Timann's discovery in 1893, as they suddenly made violet notes accessible, even as the main theme in compositions. As early as 1894, Roger & Gallet launched the solifloral perfume Vera Violetta, created by Henri Roger, one of the company's founders. It became the archetype for many subsequent violet perfumes. Alpha-ionone has a fresh violet scent, while beta-ionone has a more woody nuance reminiscent of iris. Today, thanks to their very low price, ionones are the main theme in soaps and toiletries, but it's difficult to find a delicate feminine fragrance without them.
One of the fragrances that made history was La Rose Jacqueminot (Coty, 1904), which used rhodinol along with rose absolute and alpha-ionone. This combination of a complex essential oil with two separate perfume materials gave La Rose Jacqueminot an originality, longevity, and strength unmatched by any other rose perfume of the time. With La Rose Jacqueminot, Coty introduced a new style in perfumery, where synthesis is the basis of the composition and naturalness is its essence.
Inspired by the success of Coty's masterpiece "L'Origan" (Coty, 1905), with its accord of clove, violet, and heliotrope, contrasted by the bittersweet note of anise, his main competitor, Jacques Guerlain, decided to create a sweet-floral-oriental fragrance of his own. The result was "Après l'Ondée" (Guerlain, 1906), for which he chose p-anisaldehyde, with a sweet and warm scent reminiscent of mimosa and hawthorn, as the central building blocks. Without knowing its chemical structure, p-anisaldehyde was first synthesized in 1845 by Auguste Caura through the oxidation of anise oil. The practical synthesis was then developed by Timann and Hertzfeld in 1877. In the composition of "Après l'Ondée", the aroma of anisaldehyde combines with orange-colored oil and a violet and iris accord.
Ionones were also used in Chanel 5 and are still used in many fragrances today.

The name "Ionone" was used by the original manufacturers of these ketones, the German company Haarmann & Reimer. Identical ketones, but produced by other companies, were branded differently, and the name "Ionone" was protected by the original manufacturers' registration. However, this name was not protected in all countries, and the use of the name "Ionone" has become international to describe these ketones, regardless of manufacturer. Haarmann & Reimer's patents relating to the production of ionones are over 75 years old, and global production of these ketones significantly exceeds five million pounds per year.
Ionones are very weakly soluble in water, soluble in alcohol and oils, and slightly soluble in propylene glycol. Thanks to today's advanced distillation equipment, it is possible to obtain a "white" or virtually colorless product. Commercial varieties are rarely colorless. A warm, woody, balsamic-floral aroma with a deep sweetness and moderate persistence. Its resemblance to the scent of violet flowers is legendary. A relatively powerful, sweet-woody flavor with fruity notes.
Higher concentrations in food products—for example, 20 parts per million and above—are usually “perfumed,” slightly bitter, and overly woody-floral.
Alpha-ionone is widely used in perfume compositions of almost all types. Many decades have passed since a single floral note of violet was appreciated as a flavoring for cosmetic purposes, but ionone has found many other applications. The use of ionone in rose bases is very common and generally appreciated, while in smaller quantities, ionone is used in woody, herbaceous, floral, balsamic, pine, or citrus perfumes.
It's virtually impossible to name a fragrance in which ionone isn't used to modify, blend, impart a floral character, sweeten, and so on. It's often part of a highly sought-after complex that contains large quantities of "dusty" ionones. Alpha-ionone, like most other ionones, has a noticeable effect of temporarily dulling the human sense of smell. Perfumers are aware of this and learn to handle ionones with caution, avoiding deep and repeated inhalations. Ionones are not particularly stable. With prolonged storage, they develop harsh or pungent top notes, change color, increase viscosity, and decrease solubility in alcohol. Many ionones contain antioxidants or other additives to slow their decomposition, but it's generally considered prudent to test the perfume quality of ionones and methyl ionones every 3–6 months, depending on storage conditions.
Alpha-ionone is also used in food flavorings, primarily in blends with berry imitations such as blackcurrant, raspberry, cherry, etc., as well as in spice blends, fruit complexes (for chewing gum, etc.), citrus, floral, and vanilla imitation flavors. The concentration used in the finished product ranges from 2 to 50 parts per million. One of the specific applications of ionone is its combination with pineapple, menthol, and licorice extract in some licorice candies.