What do tomatoes, cheese and mackerel have in common?
They are all responsible for umami, the slightly mysterious fifth basic taste now counted alongside sweetness, saltiness, sourness and bitterness. Umami is often likened to savoriness, but defining exactly what it tastes like can be tricky.
If you have two mini-tomatoes and chew them 30 times before swallowing you should feel a strange sensation that spreads in your cheeks. That, according to chef Kiyomi Mikuni, is the umami taste.
Umami’s scientific existence was established by Japanese chemist Kikunae Ikeda in 1908. Ikeda became curious about a particular taste contained in dashi, a dried kombu seaweed-based stock traditionally used in a variety of Japanese cuisine. He eventually discovered the amino acids in glutamate responsible for the umami taste, and also present in tomatoes.
For a long time, Western food researchers were skeptical about the discovery, claiming that the taste Ikeda was describing was a combination of the four other tastes. Only in 2000, when glutamate receptors were discovered on the tongue was the umami taste internationally accepted.
The reason non-Japanese experts did not identify the glutamate acid in, say, tomatoes, is because tomatoes also contain sweetness and sourness, making the identification of umami difficult. Later, other amino acids responsible for the umami taste were discovered, giving further proof of its importance.
It was later revealed that western ingredients such as mushrooms, cheese and meat also have the umami elements. It's no surprise that pizzas are so delicious – they are a festival of umami-rich amino acids. Researches have also revealed that umami is one of the first tastes a human being encounters, as breast milk is also rich in glutamates.
Mikuni revealed that there are at least two more candidates, including the tastes found in oil and calcium, which could enter the basic taste hall of fame.
“A big part of our sense of taste is still unknown to us,” Mikuni said with a grin. “We do not know its limits, and that's why cooking is so much fun.”