Perfumery Materials: Pyrazines, Burnt/Caramelised/Maple Notes

One of the new trends that's gaining momentum as we speak is the one focusing on slightly "burnt", caramelised, overcooked notes that are remininscent of toast, sticky brunt toffee or maple-laced warm milk; a darker shade of gourmand if you will! Suffice to take a look at Jeux de Peau by Serge Lutens (shades of fresh toast) or Sensuous Noir by Estée Lauder (a crème brulée almost taste under the patchouli), not forgetting Minuit Noir by Lolita Lempicka which follows the path where L de Lempicka left off. Gourmand fragrances (a subset of orientals focusing on foodie notes) aren't going anywhere; even genuine gourmet food companies are issuing their own fragrances, if Payard is anything to go by. But a more nuanced, more sophisticated approach is ushering in, hooking up even die-hard purists.

But which materials are responsible for these flavours, these seemingly off-notes that nevertheless entice our taste buds as much as our intelligence?

One category is pyrazines, organic compounds with a ring structure of at least two elements. Naturally occuring in a variety of foodstuff (such as green peppers but also peas; plus they're used to enhance the "roast" factor of coffee and cured meats and to enhance the flavour of potato salad). In fragrance terms Lutens and Chris Sheldrake manipulated the roasted aroma of pyrazines into a composition that enhances the comfort factor with creamy sandalwood: eh voilà, Jeux de Peau was born!


Other molecules that render indispensable gourmand notes are:

Maltol or 3-hydroxy-2-methyl-4-pyrone...C₇H₈O_{3
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Although we have come to consider Ethylmaltol (see below) the standard "cotton candy" (candy floss) note of reference in perfumery, maltol is a naturally occuring chemical that can been found in chicory, cocoa, coffee, roasted malt, bread or even strawberry and which gives this spun caramelized effect we have come to associate with fair grounds.
Ethyl Maltol or 3-hydroxy-2-ethyl-4-pyrone...C₈H₁₀O_{3 ..............................}
Ethyl Maltol is the ethyl analog of Maltol, of course, but this time the molecule is synthesized in the lab and is not to be found in nature: hence the boosted effect; almost 500% more than simple maltol!
Smell Thierry Mugler's Angel, the trendsetter of ethylmaltol and patchouli orientals ~with a nod to childhood~ from 1992 and be prepared to be blown away by its potent spun sugar, cotton candy note!

Furaneol^(R) or 2,5-Dimethyl-4-hydroxy-3(2H)furanone ..C₆H₈O_{3
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This is a molecule which was taught to samba from the craddle: it naturally contributes largely into the chemical make-up of several tropical fruit (guava, lychee, pineapple) as well as other less exotic ones (strawberry, raspberry, tomato). The fact that it is used in roasted products as well (such as corn tacos, roasted almonds, popped pop-corn or roasted coffee) contributes to its perception as a "roasting" note. I hypothesize that it's at the heart of Dior's Miss Dior Chérie, a composition based on the tension between strawberry and freshly cooked pop-corn.

Cyclotene or 3-Methyl-2-cyclopenten-2-ol-l-one ..C₆H₈O_{2
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With Cyclotene we enter the maple section of notes: Although fenugreek solid extract is used to render a maple-suryp note (indeed it was the only extract source of caramel-maple notes till the discovery of these other ingredients), actual maple suryps are further aromatized with Cyclotene; thus creating the vivid association of the molecule's odour with our perception of how maple suryp smells like! Is it maple that smells of Cyclotene or Cyclotene that smells of maple? Naturally occuring in fenugreek seeds, it's also very common today in roasted sugary products such as coffee desserts, licorice sweets, desserts with roasted almonds and, apart from fenugreek seeds, it also occurs in cocoa and coffee.

Sotolon or 4,5-Dimethyl-3-hydroxy-2(5H)-furanone..C₆H₈O_{3
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Sotolon is the key ingredient in roasted fenugreek seed and brown sugar, which is as yummy a combination as any, hence its reference as "caramel furanone" or "sugar lactone" as well as "fenugreek lactone". When it's really concentrated, it takes on curry-like tonalities while on lower concentrations it can stay within the "caramelised sugar on the pan" range of odour.
But Sotolon also possesses notes that match boozy tonalities, as it's occuring in sake, rice wine, and botrytized wine. Remember the niche fragrance Botrytis by Ginestet, meant to reproduce the "noble rot" of a fungus on the Sauternes grapes? It's got Sotolon in it, blending the pain d' épices, candied fruits and honey notes into one seamless blend.
Although Sotolon is thousands of times more powerful than Cyclotene, the modern flavours industry is using the even more powerful maple furanone (one of the most potent flavor chemicals known to man) , this time for the enhancement of the flavour of soy sauce. Thankfully, this ingredient hasn't bombasted commercial fragrances yet, but who knows what the future holds.


Related reading on Perfume Shrine: Immortelle/Helichrysum: golden sunshine of the Med , Perfumery's Raw Materials

Ref: Leffingwell Photo of maple syrup by Martin Eager