A Tasty New Development

Hey there, readers! You may have seen the chatter this morning, or perhaps you've seen Carmen's or Andy Revkin's write-ups?

It's time to hear it from the dog's mouth: I'm now part of the Food Matters family over at Scientific American!

Now, this doesn't mean I'm closing up shop here at Just Like Cooking; far from it. Following Ash's example, I'll write about my love of food chemistry over there, and my love of [everything else] over here. Sound good?

Have a peek at Bora's intro post to learn more about all the new faces, and check out all the smart things my co-authors have written over the years.

Looking forward to this exciting new adventure. Thanks again to everyone who made it happen, and for all of you here at JLC for reading.

Book Review: Gulp

Note: For other reviews, check out Neurotic Psych, Science News, the New York Times, or the Boston Globe.

It took a bit longer than anticipated to finish Mary Roach's new book Gulp: Adventures on the Alimentary Canal.  Not any fault of hers - the book reads glibly enough, with just enough science to hold my interest (and just enough yuuuckk for wider audience appeal!).

Other reviews (see above) have explored the book's structure, which jokes hit or miss, and whether it holds water compared to Roach's other works. I'm going to take a slightly different take:

Gulp is a chemistry love story, wrapped in fart jokes and gallows humor.

As before, I'm just going to jump around to different chapters for moments I unexpectedly learned something about the unique chemistry of taste, smell, digestion, and excretion.

Page 44: "Pyrophosphates have been described [to author Roach] as 'cat crack.'"
(Finicky eater? Add some phosphates!)

Page 56: "A serving of liver provides half the RDA for vitamin C, three times the RDA for riboflavin, nine times the vitamin A in the average carrot, plus good amounts of vitamins B12, B6, and D, folic acid, and potassium."

"What's the main ingredient in dog food palatants? Liver."

Page 73: Huh: L-cysteine extracted from human hair has been used to make fake soy sauce.

Page 110: Baby saliva contains extra lipase, to compensate for "...the newborn's high-fat, 100% whole-milk diet."

Page 111: Fabric softener works by "...ever so gently digesting the fibers" using enzymes.
[Interestingly, howstuffworks.com, Wikipedia, and Answers.com seem to disagree, attributing the effect to static dispersal]

Page 142: Why does fruit crunch? "When you bite into an apple, the flesh deforms, and at a certain moment the cell walls burst."

Page 175: Oysters go into shock at low pH. Thus, "Researchers who need to sedate crustaceans use seltzer water."

Page 226: Apparently, in the early days of NASA space-flight, researchers expressed real concerns over capsule explosions due to methane and hydrogen gas produced during astronaut digestion.

Page 234: "Bean gas" results from complex oligosaccharides passing through the stomach and fermenting in the small intestine.

Page 245: Three sulfurous compounds contribute to most human flatulence odor: hydrogen sulfide, methanethiol, and dimethyl sulfide (the redolent-of-farts haze formed after a successful Swern oxidation.)

Page 247: Bismuth subgallate pills "...reduce 100% of sulfur gas odor, [functioning like an] 'internal deodorant.'"

Page 263: More on hydrogen sulfide, the "...hottest area in biomedicine right now: it's a gastrotrasmitter, a signaling molecule, [and] it has tremendous therapeutic value."

Page 275: Rats and rabbits engage in autocoprophagia - eating their own feces - as a method of supplementing vitamins (B5, B7, B12, thiamine, riboflavin) produced only by bacteria in their intestines.

Page 316: When processing "samples" for a stool transplant, a blender is modified to deoxygenate and store the material under nitrogen, thus promoting survival of anaerobic gut bacteria.

Overall, I really enjoyed the book, though I couldn't escape feeling that certain chapters (4, 11, 16?) had been shoehorned in from other projects only tangentially related to these "alimentary adventures." One interesting thing differentiating Roach's writing involves asides* to the reader, giving one the feeling that you're leaning in for a secret bit of wisdom...or an extra-terrible pun.

Seeing that Mary's last few books have dealt with (decidedly dirty) topics like death and digestion, I can only assume the next book will be titled Waste, and will uncover the exciting science of garbage and landfills.

If she writes it, I'll be first in line for a copy.

*Seriously, I know I'm supposed to 'kill my darlings' in writing, but I can't resist doing this sometimes...**
**Nor, apparently, can I resist ellipses. Dangit.

'Green' Coca-Cola

Credit: Soda stream USA

I really enjoyed hearing Bob Mondello's NPR blurb about the debut of "Coke Life" in Argentina. Apparently, this soda contains stevia and table sugar, and sells in a plant plastic derived bottle. It's not as calorie-laden as traditional Coke, and bills itself as "green" (renewable). Thus, the new logo Coca-Cola rolled out: a green background, in place of the traditional red known the world over.

I have a secret: I've often wanted to peer behind the scenes as a Coca-Cola chemist. Think about all the different stuff you'd get to play with! Considering sweeteners alone, you have Diet Coke, Coca-Cola, Coke Zero, and now "Coke Life," which use aspartame, high-fructose corn syrup, sucralose, and stevia, respectively. Not just those, but dyes, vitamins, stabilizers, emulsifiers, preservatives, and much, much more. Best part? If you invent something exciting, you get to see it used by billions of people - more than your average pharmaceutical (and a much shorter development cycle!).

It's interesting to speculate on why certain artificial sweeteners didn't make the Coke cut. Certainly, lead acetate didn't - ask the ancient Romans why not. But diner table stand-by saccharin didn't, either. Perhaps too much bad press on its tenuous ties to cancer? And why not go back to using a truly "natural" sweetener, like sugar or honey? Cost plays a role here, as does consumer preference.*

I look forward to trying "Coke Life" myself. If anyone from Argentina reads this, let's work out some shipping arrangements.

*To me, HFCS tastes overwhelmingly cloying, but I've heard dedicated Coke drinkers describe saccharin as "metallic," aspartame as "sharp" or "bitter," and stevia as "too sweet" (Ha!). 

Time's Terpenoids Need Chem Context

The latest issue of Time discussed drought impact on food flavoring molecules: Health & Science section, p. 26. Seeing words like sucrose, sulfur, and capsaicin in a major magazine perked up my chem "spider sense," but I balked at the description under "bitter" vegetables like dill, fennel, or carrots. The exact passage reads:

"Chock-full of terpenoids, or aromatic compounds, that become especially concentrated during drought conditions"

OK, Time, what did you mean, exactly? Context clues are key - the author wants the word "aromatic" to describe sense impact, or how these compounds taste and smell. Of course, when I think "aromatic compounds," I imagine cyclic molecules with lots of pi electrons, stabilized through conjugation.

Can't we both be right? Of course! Certain compounds fit both criteria - they have both an aromatic ring and also smell good. Then, of course, there's terpenoids that don't fit either rule. Most play to the middle: they're odiferous, but would still make Huckel cry himself to sleep.

Either way, a little context goes a long way to helping people understand the wide array of flavor compounds in their food...without causing chemistry consternation.

Update (8/9/12) - Fixed image, deleted THC, added thymol as a more representative volatile terpenoid