Umami, the fifth taste, is the Japanese word for delicious. Kombu is traditional umami-rich ingredient used through many generations in Japan.
Five basic tastes and functions (crucial to human life):
Sweet Presence of sugar, energy in foods
Salty Presence of minerals in foods
Sour Potential presence of poison or danger in foods
Bitter Potential presence of poison or danger in foods
Umami Presence of glutamate (protein) in foods