Wednesday, April 6, 2011

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...C7H8O3
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...C8H10O3 ..............................
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 ..C6H8O3
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 ..C6H8O2
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..C6H8O3
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


  1. Really interesting. You are really good at describing these molecules so that the reader has a full sensory experience! Thank you.

  2. dleep16:49

    Very informative. Thank you.

  3. TFC,

    thanks, how kind of you to say so! Glad that it doesn't read as a boring science school textbook; always a risk when becoming technical.
    Hope it's interesting to perfume lovers to find out how things "tick".

  4. Dleep,

    thank you for commenting to say so, I'm very glad it looks helpful.

  5. Rappleyea19:48

    I've just spent an enjoyable hour catching up here! You've been prolific. I always love your materials posts - they help me to understand and to appreciate what I'm smelling in fragrances.

    OT here, but as I said, I've been catching up... aromatherapy books differentiate between orange blossom and neroli as OB comes from the flowers of the *sweet* orange tree, while neroli is from the flowers of the *bitter* orange tree.

    Excellent writing as always!

  6. Asali21:21

    An excellent read while also being very informative and interesting. Thanks a lot :-)

  7. Anonymous08:17

    Thanks E, great article. Great that you continue with the Materials series. I wanted to ask you for Series about oriental scents. I just recently started to like them and it looks like it will be a big love.:-)

  8. Anonymous11:58

    Excellent technical stuff as always E. Thank you

    I am more of a fan of the fenugreek/malpe syrup aspect of pyrazines. The burnt sugar aspects have left me a bt cold, probably because they are always combined with foody notes. In the end I have the impression that I am smelling scented candle. I was expecting a bit more from Jeu de Peau for instance, than the reproduction of a continental breakfast.

    Where does immortelle fit into the pyrazine story? Are the similarities with fenugreek and curry owed to pyrazines?

  9. D,

    hi darling, thanks for stopping by! Hope you had an enjoyable hour on these pages :-)

    The materials posts are well received, I guess for the reason you state. It's fun to compose because they help me organise my thoughts in simple terms as well.

    Now as to the differentiation, I believe both trees yield an OF absolute. In Aftel's (and Lawless's) book the bigaradier is mentioned for that purpose, but now I wonder whether the aromatherapeutic properties are enhanced in one over the other (could be!).

  10. You're welcome Asali. Thanks for saying so.

  11. Lavinia,

    I'm jotting it down as a request that shall be materialised then! ;-)
    It's not like I'm short of materials to dissect.

    Thanks for the suggestion, I do welcome them.

  12. Thanks D, flattered you think so.

    I have to say that the overindulgunce in sugary notes does give a bit of a rot on the tooth, and modern fragrances can be said to have been overexploitative of that, so I can sympathise. I liked Jeux de Peau myself, but more because I saw it as a woody oriental than as expecting to see it as a toasty scent. It reproduces the effect well (continental breakfast is a precious descriptive!! LOL) but if one isn't told that, I think they're bound to focus more on the nicely warm sandalwood. It does remind me a bit of Santal Blanc (which is as warm and cozy as any). Then again, this is Serge and he could do a weirder one. There's always next time ;-)

    Fenugreek gives an extract that is curry-like in its odour profile. (if you have smelled the pills given to lactating mothers or drunk the tea made from it, you know what I'm talking about all too well). Now maple syrup was aromatized with fenugreek in the past before the more isolated molecules were discoveredm because it boosted the natural flavour. And so the association was created. The 4 most usual maple flavourings are cyclotene, , ethyl cyclotene, sotolon and maple furanone. They're all related in a molecular level without being pyrazines, but sharing an odour facet.
    Immortelle absolute is sometimes used in tobacco flavouring I believe alongside the cyclotene, so maple and immortelle might share the curry-burnt sugar facet through that as well. (cigarettes sport pyranones as well which are related to pyrazines and these are all also related to furanones such as the ones described above)

  13. A very helpful post, thank you... although I have to say that, personally, I hope the trend for burnt gourmands is short lived.

  14. P,

    thank you for saying so.
    Well, it's at least better than the fruichouli! ;-)


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