So today I went for a nice, long run (wanted to earn up enough points for a glass of wine or two tonight), came home, and started making a green tomatillo salsa for enchiladas a la Guy Fieri on the Food Network.
Tomatillos, man.... They are so so so good cooked and especially in salsa verde, but fresh they STINK!!! I got so concerned about the lavatory-esque odor coming from them that I began to look it up online to see if they'd gone bad. Seriously, smelled like poo. The the other palate in the house came home and told me I was crazy, they smelled a little but not bad and not overly strong.
Well, I did my internet search, and found:
"Truth be told tomatillos stink. Literally. The paper husk smells like rotting dirty socks."
http://mykidseatsquid.com/2010/04/103/
There's a comment: "I thought this would be good, but when you eat it tastes like a stink bug smells. It's the tomatillos...." on this recipe:
http://allrecipes.com/recipe/tomatillo-guacamole/
So, based on these various sources, it sounds like tomatillos are kind of like durian. Durian are a wonderfully tropical custardy fruit that many people say smells alternatively like dirty socks or a lavatory or something disgusting. I can't smell that on them at all, only tropical goodness. The odor in durians is due to a chemical called a "thiol." These chemicals are what make natural gas smell (methane has no odor so they add the thiol as a harmless warning odor), skunks stink, and durian smell. It looks for all the world like sensitivity to thiols is genetic, as neither my dad nor I find them unpleasant at all, and have to experience them at high concentration before we even notice they are there. This has led to a few mishaps around the laboratory.... another post for another time.
Obviously, it can't be thiols that are making tomatillos stink, if so there would be a lot more press on malodorous tomatillos. (And the other palate in the house would've been knocked out the door by the stench if I could smell them at all....) Therefore, in my mind, at least, it must be due to some other scent chemical that people with a genetic insensitivity to thiols learn to notice to warn us away from things like poop and dirty, rotten socks. It's possible that people who can smell those nasty thiols compounds never really learn to pick up the compounds I associate with nasty things simply because they never have to - those molecules that I find nasty are always masked to other people by the blast to the olfactory from the thiols.
Anyway, I would be interested in hearing other interpretations of the data I present.... as one random scientist to another.... :-)
Good (non-malodorous) eating!
Seems a bit primitive:
ReplyDelete"The odor in durians is due to a chemical called a "thiol." These chemicals are what make natural gas smell (methane has no odor so they add the thiol as a harmless warning odor), skunks stink, and durian smell."
I'm going to assume that the first mention in singular ("chemical") was in error--thiols are a whole class of compounds, not to mention that at least 14 different volatile thiols have been recently identified in durian in a full profile of its aroma (a full third of all aromatic compounds identified in durian).
At the moment, I've been able to find no evidence (scientific studies) that sensitivity to any particular thiols is genetic. There is, however, some evidence that some plants do indeed evoke genetically coded reactions. One that's known to be genetically linked is coriander (a.k.a., cilantro). Although many people love the aromatic profile of coriander and it is prominently featured in cuisines of many cultures, a substantial fraction of population reports that it tastes/smells like "soap", "dead bugs" and other unpleasant things. It does not, however, come close to the rotten onion/egg smell that is associated with ethyl mercoptan--the original thiol that was added to commercial natural gas to make leaks easily detectable. (A more common additive today is t-butyl mercoptan--mercoptan and thiol is the same thing.) Thiols are also responsible for particularly strong odors in mouse and cat urine, as well as skunk defensive discharge. But they are also present--and are generally considered pleasing aromatics--in grapefruit, papaya, mango, and, most importantly, roasted coffee. I am not aware of thiols being responsible for tomatillos odor, nor do I find the odor particularly unpleasant, but that could just be my ignorance. If thiols are present in coriander, that might be a point to score for genetic predisposition against thiols. But they are also present in hops, particularly some of the newer, more sulfury varieties such as Citra and Mosaic. As a result, a lot of people taste/smell onions, garlic and cat urine in some of the most popular, highly-hopped craft beers. It is a subject of much discussion on beer forums.
Thanks for the response! I did try to keep the language friendly to the general user. Mercaptoethanol is the primary odiferant added to natural gas, while pentathiol and hexathiol are the primary odiferants associated with skunks and durian.
DeleteThe suggestion that my nasal response is different from others is well supported, and I agree and indicated that blaming it on genetics is easy but as yet unconfirmed.