> It's called "umami" (I'm not dissin yer mom, either). The taste receptor > reacts to L-glutamate which can act as a marker to high-protein foods. It > goes on to say that MSG (monosodium glutamate) maybe popular due to this. For a more detailed account of umami and the other senses involved in what we think of as "flavor," see: http://www.monell.org/sensation.htm#Taste