Ripe tomatoes, which are rich in umami components ウィキペディアには熟したトマトの例があって・・・笑ってしまった。 説明できないときは、これの英語版をコピペしてスカイプチャットに添付します。
Umami /uːˈmɑːmi/, a savory taste, is one of the five basic tastes (together with sweet, sour, bitter and salty). A loanword from the Japanese (うま味?), umami can be translated as "pleasant savory taste". This particular writing was chosen by Professor Kikunae Ikeda from umai (うまい) "delicious" and mi (味) "taste". The kanji 旨味 are used for a more general sense of a food as delicious.
People taste umami through receptors for glutamate, commonly found in its salt form as the food additive monosodium glutamate (MSG). For that reason, scientists consider umami to be distinct from saltiness.