There were originally thought to be four basic tastes, which are:
In recent years a fifth taste, often described by the Japanese word Umami, has become widely although not universally accepted. It is produced by the free glutamate?s commonly found in fermented and aged foods, and in the additive MSG (monosodium glutamate).
For many years, books on the physiology of human taste contained diagrams of the tongue showing levels of sensitivity to different tastes in different regions. There is no scientific foundation for these "maps", which were based on a misinterpretation of old research.