Umami (Japanese for "pleasant taste") is the name for the flavoring sensation produced by free amino acids, in particular glutamic acid, which can be found in fermented and aged foods such as parmesan and roquefort cheese, soy and fish sauces. They are also found in a large number of unfermented foods, such as grapes, broccoli, tomatoes, mushrooms and, to a lesser extent, meat.
The human tongue has L-glutamate receptors, which is why scientists consider minds to be separate from the salty taste.