Thursday, August 9, 2012

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


  1. Hmmm... i don't think THC has an odor. It is a high MW, non-volatile compound. The "aromatic" odor I think you're referring to is not from THC but from other terpenoids in the plant.

    1. Maybe so. I'll have to search for a better example.