Tuesday, February 19, 2008

Molecule of the week (I)

Most people like chili peppers, they're hot and spicy, but just what makes them so hot. The answer is Capsaicin (see above) and related molecules that are mostly found in the pithy material surrounding the seeds inside.

Some chilis are clearly hotter than other and there is actually a scale, called the Scoville scale that can be used to benchmark the "hotness" of chilis. A Poblano pepper comes in at around 1,000 to 1,500, the famous Jalapeno (the ones you put on nachos) come in at around 2,500 to 8,000. Pretty hot you think, oh no, there's hotter! Try the Serrano pepper at 10,000 to 23,000 or better still the habanero at a skyrocketing 100,000 to 350,000, just try eating a fistful of these, go on i dare ya!

Just why are chilis hot anyway you might ask? The answer lies in that the spiciness aids in seed dispersal. How so? What creature (besides humans of course) would bite into a jalapeno and say to itself: hmmm... food! Well, the answer is birds, yes birds. The thing about birds is that their physiology is different. Instead of getting that burning, irritating sensation that humans alone among mammals seem to like, they experience an analgesic effect, probably something like taking codeine, cocaine or maybe even heroin. Anyway, the like it, scoff down the chilis and thus disperse the seeds.

To mammals, the above mentioned capsaicin molecule is actually toxic, it can kill, far more toxic than cocaine but perfectly legal (just let's seem them try to ban chili peppers!) It registers at about 15,000,000 on the Scoville scale. Fortunately enough though, there isn't enough in any amount of chilis that you could possibly eat to actually kill you, and it's not addictive either (or maybe it is?) But what about the pure molecule itself, that could do it! Easily! Sells for about €100 a gram from Aldrich. Try snorting a line of this stuff and you're dead baby!


  1. Welcome to the Lima Bean Fields P! :-)

    I am disappointed that it's impossible to kill someone with chillis, so I suppose I'll have to stick to torture using them!

    I have a question though if this capsaicin is available and it's natural, and it can kill...would it show up on an autopsy report???

    No reason....just wondering!

  2. Oo, scary, snorting chili! Like Homer's insanity pepper, one of my favourite episodes ever.

    I'm fascinated by the analgesic effect on birds. Interesting. I wonder if people who have a high tolerance level for hot food experience similar?

    Because I assume people who like very hot chilis don't experience the same physical response some one who's more sensitive to them does. Like my friend who told her sister the dish wasn't that hot, then had to admit she was wrong, that it wasn't just wimpiness, when her sister's mouth swelled up.

  3. Oo-er. I won't be going to dinner in Midge's any time soon!

  4. Very cool first post!

    It prompted me to look on Wikipedia; wonderful distractions from work. :)

  5. Welcome Plasmonic, Nice to learn something new :)

    For me theres nothing better than a nice big baguette, with some chillis and chicken and salsa. I often wondered why manic pidgeons kept staring me out of it whenever I get one.

  6. There's no d in pigeon, you naughty naughty boy. You'll be putting a p in hamster next.

    And I'm a bit alarmed to hear of your fondness for big baguettes...

  7. PM - welcome to the blog and congrats on a great first post.

    Jo - naughty but funny.

    Ash - fair play being first on the requisite 2 letter acronym of PM.

  8. I'm loving the science!!! I'm such a science geek. Fangirl even. Hmmm...are you famous at all? Cause you know.......

  9. Strange as it may seem I have recently acquired a bottle of chilli and butterscotch liqueur and have taken a few cautionary shots of it. Somehow it works.

  10. Chilli and chocolate's great too, of course.

  11. About time! A bit of intelligence to our posts!