And Umami is Still Controversial …

Hervé This, a French chemistry professor and one of the founders of molecular gastronomy, has pointed out that one of the umami receptors, taste-mGluR4, could just as easily be a protein that sends a nerve signal—which is totally distinct from a sensory perception—to the brain. He supports this contention with the fact that molecules other than glutamate activate this receptor. And another observation on which he places great weight is that there is a whole series of different molecules (for example, other amino acids), whose taste also does not seem to be derived from a combination of the four classical basic tastes. Finally, glutamic acid is not the only possible source of umami in Japanese dashi; some also attribute the taste to the presence of alanine, which is also extracted from the konbu.