Peter Aitken wrote:

>
> >
> > We only detect 5 tastes; salt, sour, sweet. bitter and umami. In addition
> > to
> > it being one of the basic tastes, salt acts to enhance flavours by
> > amplifying
> > the response in other taste receptors. A little salt added to a sugar
> > solution
> > can act to make it taste sweeter.
> >
> >
>
> This "5 taste" idea is old and completely discredited

Where was it discredited? I did some web searching and there seems to be a lot
of support for it. Unimi was more of an asian thing but recent research has
revealed receptors that are specific to glutamate.

> . Actually it was 4
> taste for a long time, but the facts remain. I do not mean to say that taste
> has been completely explained, but the idea that the vast universe of subtle
> taste differences can be explained by 5 tastes is just plain silly. Try to
> explain the taste differences between morels, cepes, and shitake with your 5
> tastes. Between pork, beef, and lamb. Between mackerel, salmon, and bass.
> Between chicken, turkey, and duck. See what I mean? A lot more is going on
> but we do not know the details.

The best I can suggest is that it is combinations of stimulation of the specific
receptors. You might have the same problem explaining why we can perceive so
many tints and hues of colours when the visual receptor cells respond only to
black and white or to three primary colours, or how we learn to distinguish the
sounds of musical instruments when our audio receptor cells pick up only
specific ranges of sound frequencies.