Volume 92 Issue 43 | p. 31 | What's That Stuff?
Issue Date: October 27, 2014 | Web Date: October 20, 2014

What’s pumpkin spice flavor, and why do we fall for it every autumn?

The popular latte and treat seasoning contains no actual pumpkin, but it boasts plenty of food chemistry
Department: Science & Technology
News Channels: Organic SCENE, Biological SCENE
Keywords: pumpkin, pumpkin spice latte, flavor chemistry, food chemistry
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PUMPKINPALOOZA
Like chemistry, pumpkin spice is everywhere.
Credit: Starbucks Coffee (Coffee); Mike Mozart/Flickr (other images)
Collage of pumpkin spice flavored food products.
 
PUMPKINPALOOZA
Like chemistry, pumpkin spice is everywhere.
Credit: Starbucks Coffee (Coffee); Mike Mozart/Flickr (other images)

Stand down, cider: The pumpkin spice latte is the official beverage of fall. At least, that’s what a barrage of advertising and artfully composed Instagram photos would have Americans believe.

Like the zombie of so many B-grade horror flicks, every Halloween season the sweet, spicy beverage arises from Starbucks Coffee’s flavor graveyard. “Only it seems to be coming back stronger every year,” says flavor chemist John C. Leffing­well. As president of food and flavor consultancy Leffingwell & Associates, he dutifully takes reporters’ calls about pumpkin spice mania every time the leaves turn. He’s busy, given the recent proliferation of pumpkin spice products: bagels, hummus, even body butter and dog treats. Retail sales of pumpkin offerings have experienced double-digit growth for the past several years, reaching nearly $361 million in 2014, according to market research firm Nielsen.

And that figure doesn’t count Starbucks pumpkin spice lattes, which new product expert Lynn Dornblaser of market research firm Mintel Group credits with starting the trend: Starbucks has sold over 200 million since their 2003 debut.

Pumpkin spice backlash was inevitable. HBO comedian John Oliver has lambasted America’s obsession with “pumpkin-flavored science goo.” And food industry critic Vani Hari, who is better known by her blog moniker the Food Babe, triggered outrage when she wrote that pumpkin spice lattes contain “absolutely no real pumpkin.”

With apologies to the disappointed hordes, pumpkin was never the flavor intent. Pumpkins have volatile constituents, but they’re not the cloyingly sweet kind consumers expect in a dessert. A pumpkin spice product is made to evoke pumpkin pie, which, for the record, isn’t made with carving pumpkins either. The real filling is a specially bred sweet squash that is less fibrous and watery than a typical jack-o’-lantern gourd. The pie’s characteristic taste comes from cooked squash mingling with a spice mixture: cinnamon, nutmeg, ginger, and clove or allspice.

The pumpkin spice latte recipe is a closely guarded Starbucks secret. According to Leffingwell, it’s possible to create a pumpkin spice flavoring by steam-distilling pumpkin pie spices or performing extractions with solvents.

Unfortunately, it’s hard to ensure consistency in flavor strength or taste with natural spices, says Kantha Shelke, a food chemist with food science research firm Corvus Blue and a spokesperson for the Institute of Food Technologists. It’s more sustainable, she says, to use nature-identical flavor molecules in large-scale production. The combined mixture of cinnamon, nutmeg, ginger, and clove or allspice contains at least 340 flavor compounds. But human brains can fill in the blanks if provided with about 5–10% of that natural cornucopia. Major players include cinnamic aldehydes for cinnamon, eugenol for clove or allspice, terpenes such as sabinene for nutmeg, and zingiberene for ginger.

By themselves, however, spice compounds won’t create an appealing food flavor. Heating pumpkin spice ingredients together creates caramelized, slightly burned, wood-fired flavors and aroma compounds. These compounds—products of the Maillard reaction—are “what takes things from air freshener to food product,” Shelke explains. She’s not sure exactly what notes round out a pumpkin spice latte—“those are the treasured secrets of the flavor chemist,” she says. But cyclotene, the go-to compound for maple or brown sugar flavors, or vanillin are likely candidates.

That list of compounds makes sense to Donald E. Mencer. He and his undergraduate students at Wilkes University in Pennsylvania analyzed alcohol extracts of grocery-store-bought pumpkin pie spice powder with gas chromatography-mass spectrometry.

Although the data were what Mencer expected, some results surprised his students. Pinene, which turns up in cinnamon, nutmeg, ginger, and allspice, reminded the students of pine resin and wintry ever­greens, not tasty fall desserts.


UPDATE: This article was modified on September 29, 2016 to refresh its information and data.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society
Comments
Melody Bomgardner (Tue Oct 21 17:50:17 EDT 2014)
zingiberene - that's a new one to me - I love ginger flavors so I'll remember that one. For the best pumpkin pie, I use roasted butternut squash. Mmmmm.
Carmen (Thu Oct 23 15:50:29 EDT 2014)
Thanks Melody! Those ginger compounds have cool names. Zingerone is another one that comes to mind. Now I'm craving pumpkin pie...
Humanoid (Mon Oct 27 15:48:29 EDT 2014)
zingiberine ? Sounds like it tastes zingy !
Susie Bautista (Thu Oct 23 11:00:20 EDT 2014)
Beautifully written and explained. The best science communication I have read; please keep up the good work. My two favorite things: chemical structures & #PSL
George Rizzi (Wed Oct 29 10:42:27 EDT 2014)
A very nice informative article. Dr. Mencer said it all..in the flavor game the whole flavor is seldom equal to the sum of its parts.
Robert Buntrock (Fri Oct 31 15:31:11 EDT 2014)
Thanks to having a wife and a mother who are/were good cooks, I've been aware for some time that the best pumpkin pies are made from canned pumpkin instead of a jack-o-lantern pumpkin. I'm actually not that thrilled with traditional pumpkin pie but my wife used to make a killer pumpkin chiffon pie, much less rich and less filling after a big holiday dinner. I figured that the ubiquitous pumpkin flavor in foods and beverages this time of year was from mixtures of the spices. One item where I can't stand the flavor is in "pumpkin" flavored beer.
M. Goldschmidt (Wed Oct 05 18:14:39 EDT 2016)
I would love the recipe for Chiffon pumpkin Pie!!
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