Volume 93 Issue 40 | p. 38
Issue Date: October 12, 2015

Periodic Graphics: The Chemistry Of Pumpkins

Chemical educator and Compound Interest blogger Andy Brunning carves up the seasonal squash to reveal the molecules behind their color, aroma, and taste
Department: Science & Technology
News Channels: Organic SCENE
Keywords: pumpkin, Halloween, aroma, pumpkin spice flavor, canned, cinnamon, eugenol, coffee furanone

A collaboration between C&EN and Andy Brunning, chemistry educator and author of the popular graphics blog Compound Interest. To see more of Brunning’s work, go to compoundchem.com. Check out all of C&EN’s Periodic Graphics here.

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To download a pdf of this article, visit http://cenm.ag/pumpkins.
Credit: Andy Brunning/Compound Interest
pumpkin~Halloween~aroma~pumpkin spice flavor~canned~cinnamon~eugenol~coffee furanone
 
To download a pdf of this article, visit http://cenm.ag/pumpkins.
Credit: Andy Brunning/Compound Interest
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Andy’s book is now for sale in the U.K. at http://amzn.to/1FWQ8z8.
The cover of “Why Does Asparagus Make Your Wee Smell?: And 57 other curious food and drink questions” by Andy Brunning
 
Andy’s book is now for sale in the U.K. at http://amzn.to/1FWQ8z8.
 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society
Comments
Dave (Wed Oct 14 14:54:20 EDT 2015)
Any evidence for carbon disulfide in pumpkins? The odor is very much what I recall from carving them.
Andy Brunning (Mon Oct 19 13:48:24 EDT 2015)
This study (http://www.tandfonline.com/doi/pdf/10.1080/00380768.1995.10419589), which looked at sulfur-containing gases emitted by various plants, didn't find any emission of carbon disulfide from pumpkins. It did find emission of DMS and methanethiol, however, which could, to some extent, account for the similarity in smell.
MPanda (Wed Oct 26 22:49:45 EDT 2016)
Excellent information even for an old Organic Chemist like me. When I was teaching the organic chemistry laboratory courses in the 1980's at UC Santa Cruz, the students used to isolate beta-carotene from carrots and eugenol from cloves along with their characterization using IR and NMR.
J. A. Beck (Wed Oct 14 15:01:30 EDT 2015)
Perfect timing for your article. My home is filled with the wonderful aroma of fresh pumpkin being cooked in preparation for holiday pies and other treats. The spices will come another day. Canned pumpkin? NEVER!
Frederick  (Thu Oct 15 04:05:17 EDT 2015)
Thanks so much for this information. What are the IUPAC names for CINNAMALDEHYDE, EUGENOL, COFFEE FURANONE, and FURFURAL?
Andy Brunning (Mon Oct 19 13:41:32 EDT 2015)
The IUPAC names are as follows:
- Cinnamaldehyde: (2E)-3-phenylprop-2-enal
- Eugenol: 4-Allyl-2-methoxyphenol
- Coffee furanone: 2-Methyldihydrofuran-3(2H)-one
- Furfural: Furan-2-carbaldehyde
Jeff (Wed Oct 28 09:17:59 EDT 2015)
What's missing here is a comparison of cooked fresh pumpkin, the way you would prepare it to use in a pie, and the canned variety. My guess is they are pretty close to identical. It's hard to imagine those volatiles sticking around through any cooking process, home or factory.
Andy Brunning (Fri Oct 30 12:49:43 EDT 2015)
That's a very fair point. I'd guess you could easily substitute in 'cooked pumpkin' for 'canned pumpkin' here and there probably wouldn't be a whole lot of difference between them. Unfortunately, I'm not aware of any study comparing the two – which is, of course, not to say that such a study doesn't exist somewhere.
Kurt (Wed Oct 26 02:44:09 EDT 2016)
Although when comparing canned to cooked "baked" fresh pumpkin, there is a significant difference in taste. We almost always use fresh pumpkin for making pumpkin pies and people who have historically disliked pumpkin pie made from canned pumpkin tell us that they now like pumpkin pie if it's made from fresh baked pumpkin. So, I wonder what are the possible chemical difference between the two processes.
Robert Buntrock (Mon Oct 31 21:43:39 EDT 2016)
As I recall, from other descriptions of pumpkins, is that different pumpkins (gourds)are used to prepare canned pumpkin so the chemical compositions and aromas would differ. My wife, a good cook, said that jack-o-lantern pumpkins did not make good pumpkin pies so we always used canned pumpkin.
Keane Glessner (Thu Oct 27 09:25:36 EDT 2016)
Thanks for info. I use real pumpkin in SensUlistic scrubs and Fizzies adding a hint of pumpain pie spice and minimal cinnamon leaf oil! Gr8 to have this post!
Pteridine (Fri Oct 28 23:27:23 EDT 2016)
One thing to consider is that "canned pumpkin" is actually a mixture of Acorn, Butternut and associated squashes and not what we would call a pumpkin. Even the small "pie pumpkins" that some stores sell are not actually a true pumpkin but just another variety of miniature squash. That is why it smells differently than the carved pumpkin.
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