Scientific American (repost of something in wrong spot)
- Peter Feb 21, 2001 07:04 AM
I accidentally posted this message in "Not about food",
so I am reposting it here. Sorry about that
In the new Scientific American there is an article on the sense of taste. I found it quite interesting.
Two notes: One, the "taste map" of the tongue is apparently just completely wrong; it was based on 18th century research, and keeps getting passed on from textbook to textbook, but has no basis in reality.
Two: The new taste of "unami" is apparently accepted by only a small minority of taste researchers. Most of them (including the authors of the article) stick with the original four tastes.
Even if a map is 'wrong' it can still be a useful guide. Most people still perceive sweetness at the front, bitterness at the back and acidity at the side - even if those tastebuds are all over the tongue.
Kepler's Laws still 'worked' for all known planets; Newton's Laws still work for most applications - even if they're strictly 'wrong' - the Einstein corrections make no difference - FOR MOST PRACTICAL APPLICATIONS.
But thanks for the reference - there's been a real shortage of stuff on taste (and smell) anywhere. The most interesting thing for me is that the same tastes 'change' when seasoning is added.
Maybe we also need a psychological theory of taste.
And why does fat taste so good?
re: Alan Gardner, Toronto
I believe fat 'tastes so good' because of its 'organolipid properties,' which basically means it helps transport flavors to the nose and hold flavors on the palate. I got that six-bit term from a guy I know who is trained in flavor chemistry.
Now, I'll allow someone who really understands this to correct me.
re: Jim Dorsch
I recently read (sorry - forget the source - probabaly NY Times) that we're genetically programmed to think that fat tastes good from way back in the days when we foraged for food and it was hard to come by. Was an evolutionary advantage to sock away calories in fat when it was available.
Our culture and food technology have changed much more rapidly than our biology, tho, and that's why so many Americans are so overweight. We still go for the fat, even tho we have more than enough of it in our diets.
re: Lisa Z
That's the accepted wisdom - but I just don't buy it, being a sceptic by nature. Of course, my original comment was in the context of taste - which requires a jump to hypothesize that what tastes good is evolutionally biased. I suspect food is far more cultural than evolutional (too many multi-syllable words already).
Also fats tend to be heavy - I can accept that the flavours linger on the tongue - but again a stretch to have them carried up to the sensory receptors.
So, to the point. Scientists may have a better 'map' of the tongue. But where's the understandable explanation for different tastes and smells - whether or not unami exists (and if it does, my guess is in fat!).
re: Alan Gardner
i have only an extremely vague notion of this, the residue of a high school chemistry or biology class, but i think the idea of fats carrying scents to sensory receptors might have something to do with the chemical makeup of fats, which is such that they can more easily bond with the kinds of chemicals that are flavorful. those fatty chains i believe have, like, those hydrogens on each link that are missing electrons and wanting to bond with whatever is floating around.
it's those same properties that make fats such great energy storehouses, so there would seem to be a link between this flavorfulness and the value of fats as nutrients. maybe flavor became important partly because it became associated with nutritious foods. it makes it easier to tell if food is rancid, as well. as a system it's quite elegant, really--evidence of an divine creator?
i had an elderflower cake last night that was evidence if not proof of a divine creator. there was a lot of fat in that cake.