Thread: The umami of Marmite

I hope this has enough science in it (although admittedly not much) to justify being in Biology. Feel free to move it.

This is another tidbit from Proust Was a Neuroscientist by Jonah Lehrer. We are told that there are only four taste sensations: sweet, sour, salty and bitter, but the (allegedly) delicious taste of the Japanese dish dashi, made from seaweed, didn’t seem fit within any combination of these four sensations. The word umami, meaning deliciousness, is used to describe the taste of dashi.

It turns out that the chemical ingredient responsible for umami is L-glutamate, an amino acid that the tongue can taste, and the salt in seaweed that gives dashi its umami is MSG.

Western science continued to insist that there are four, and only four receptor types on the tongue, and none of them can taste L-glutamate. However, in 2000 (Chauderi et al) and 2002 (Nelson et al) two sets of umami receptors were indeed discovered. (This claim is apparently still somewhat controversial.)

L-glutamate is produced when protein decays, which is why it turns up the fish sauce of ancient Rome. According to Lehrer, “Umami even explains (but doesn’t excuse) Marmite, the British spread made of yeast extract, which is just another name for L-glutamate.” It is also produced when meat is browned in a hot pan. When the cook deglazes the pan with water, wine or brandy the burned meat scrapings become part of the chef’s stock, or a reduction for a sauce, so L-glutamate is largely responsible for the Escoffier revolution that put French cooking on the map.

Lovely stuff. And I like marmite. I thought the umami taste receptors were now an established fact? Is it still controversial?

So is the reason that people love or hate the stuff down to the fact that some have this extra taste receptor? It seems quite logical. If it is 'delicious' and those who do not have the 'delicious' recptor don't find it 'delicious' because they don't recept to it?

Is it still controversial?

Maybe not.

http://www.vivo.colostate.edu/hbooks...ric/taste.html

So is the reason that people love or hate the stuff down to the fact that some have this extra taste receptor?

Overuse of MSG in Chinese restaurants has given it a bad name, but are there people who actually hate the taste, or can't taste it? The claims that used to be made about allergic reactions to MSG (headaches etc.) seem to unsupported, from what I've read.