Wednesday, May 30, 2018

Damask roses and black tea

So excited to be going to World Tea Expo, where I hope to carry out an experiment!

Damask rose. Image from Wikimedia Commons.

One of the characteristic chemicals in black tea is β-damascenone, a member of the category of chemicals called rose ketone, because it is characteristic of roses—damask roses in particular, as you can guess from the name.*


β-damascenone
According to William Luebke, this chemical has a "natural sweet fruity rose plumr grape raspberry sugar" odor, while according to Gerard Mosciano it has a "Woody, sweet, fruity, earthy with green floral nuances" odor.** To me it has a warm, sweet, deep, rich, dusty-rose odor reminding of the women's powders of my youth.

Turns out that the smell of β-damascenone is significantly more intense to some people that others.  This difference has been attributed primarily to a single nucleotide difference rs2220004.*** Unfortunately, neither 23andme nor Ancestry DNA report results for this snp, so I can't tell you whether my impression is the one attributed to the ability to smell the compound.

However, I do not "get" the green or the woody or the earthy, so perhaps I only sense part of the aroma, even at the high concentrations at which I sniffed it just now. According to McRae and his colleagues, about 1 in 10 people of European descent have the version of the snp that is less able to smell the compound. That said, β-damascenone appears to activate a number of different odor receptors, and it may be that a change in one of these receptors can alter the perception profile of the odorant without changing its perceived intensity.

At WTE I'm planning to go around with a small vial of β-damascenone and have people tell me what they smell, and see whether people do in fact describe it differently.

So exciting!

* The damask rose is one of the "Old Roses"—early hybrids whose origins and cultivation histories are the subject of much speculation. Genetic data suggest that the damask rose developed in Central Asia, but when it was brought to the Middle East and Europe is unknown. It probably gets its name from Damascus in Syria, which was under siege during the second crusade in 1148. Crusaders may have then brought the rose back to France and given it its name, though the plant was known in Europe before then. Damask roses are the major source of rose oils, rose water, and rose sugar, known as golab, and in other sweet dishes, an ingredient in ras al hanout, and in a number of  culinary delights from the Middle East, India, and Central Asia.

** As reported in the Good Scents Company website: http://www.thegoodscentscompany.com/data/rw1021911.html#toorgano

*** Jeremy F. McRae, Sara R. Jaeger, Christina M. Bava, Michelle K. Beresford, Denise Hunter, Yilin Jia, Sok Leang Chheang, David Jin, Mei Peng, Joanna C. Gamble, Kelly R. Atkinson, Lauren G. Axten, Amy G. Paisley, Liam Williams, Leah Tooman, Benedicte Pineau, Simon A. Rouse, Richard D. Newcomb. Identification of Regions Associated with Variation in Sensitivity to Food-Related Odors in the Human Genome. Current Biology, Volume 23, Issue 16, 2013, Pages 1596-1600, ISSN 0960-9822, https://doi.org/10.1016/j.cub.2013.07.031.

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