Umami

(image from healthline.com)

I will cover cryobiology, a subject that came up in the comments last week, on Tuesday, but today I want to talk about something I came across a few weeks ago while listening to The Splendid Table on NPR (a cooking show).

The host talked about some mysterious taste called umami that I didn't remember ever having heard of before. Remember high school biology? The teacher had a giant tongue up on the overhead projector and pointed to various places on it. "This is where we taste sweet. Sour is hear, bitter is here, and salty is here. These are all the tastes."

Was I the only one thinking, "yeah right!"? I was properly indoctrinated though and I have found myself in front of groups of students with my handy dandy giant tongue, saying the same things. But, aha! There is another one. Those brilliant high school students knew it all along. (You suppose there might be other tastes hiding out on there that they haven't discovered?)

Umami means yummy(I don't speak Japanese and the experts said delicious but it sounds like yummy to me) in Japanese because the man who tracked this taste down to a chemical called glutamate was Japanese. If glutamate is sounding familiar to you, think MSG. Some people have a hard time with MSG and this taste seems to be triggered by all kinds of meats and cheeses, so what the food world really needs is a replacement for MSG that's more like the chemicals in meat that cause the taste.

That leads us to the receptor for the umami taste, which looks like (or would if you could see it) a very tiny venus fly trap. I only know that because the scientists named it the Venus Fly Trap Domain (there seems to be a venus fly trap domain involved with other kinds of receptors too). It seems to take two chemicals to cause this trap to snap shut. So far as I have been able to tell, nobody has put this taste on the map of the tongue yet and so I am unable to add it to my giant tongue transparency...

several reasonably reliable sources (including this one) tell me the map of the tongue is a myth anyway and you can taste most flavors all over the tongue. This seems strange to me since the professors in grad school had me teach a lab about this (and later I taught the same lab myself) to hundreds of students and it all seemed to work out fine... maybe college kids report what they think they are supposed to? I'm not going to repeat the experiment right now, but maybe I will later.

Links:

This paper is talking about Venus Fly Trap domains and allosteric control of agonistic affinity.

This Wired article is a lot easier to understand.

This article from Chemistry World shows us how chemicals work together to make the umami taste stronger.

Word of The Day

Agonist: A chemical that binds to a receptor and causes it to act in some way.