Glutamate is the purest taste of umami, the fifth basic taste. Umami taste receptors have a special affinity for free glutamate.
The idea of umami as a basic taste was not easily accepted internationally. In 1979, Japanese scientists introduced their results to the world in a paper on “The Umami Taste” at the Joint US-Japan Science Conference. For too long, researchers had focused on only four tastes (sweet, salty, bitter and sour) and, consequently, only described four. However, this paper was an affirmation for umami taste among taste physiologists.
After 1982, many scientists in Japan, America and Europe joined in the research on umami. Psychophysical and electrophysiological studies showed that umami is independent of the traditional four tastes. Furthermore, specific receptors for glutamate representing umami substances were identified in 2000 and 2002.
Now it is widely accepted that umami is the fifth fundamental taste, and the word umami is now being used universally.
Tradition of Glutamate and Umami Seasoning
Of all the foods and seasonings that are rich in glutamate, fish sauce goes back the furthest. In the Greek and Roman civilizations of antiquity, fish sauce was widely used as a seasoning.
The ruins of many large fish-pickling factories have been unearthed along the Mediterranean coastline. A seventh century list of seasonings names this fish sauce “Garum”. Records dating back to the year 968 tell us that the Byzantine Emperor Nikephoros II entertained Pope Otto I’s messenger with roast lamb dressed with onion, leek and Garum. Salty fish sauce can thus lay claim to more than 2,500 years of history. This makes it the oldest umami seasoning in the world.
Today, the human appetite and predilection for the amino acid taste is as strong and healthy as ever. In modern Italy, it is glutamate that contributes to the appealing taste of tomato sauces that accompany the country’s famous pasta dishes and pizzas. Glutamate is present in meat extracts (such as Bovril) in western countries and in the seaweed and dried fish, which are used to make soup stocks in Japan.
A team of scientists in the US have recently discovered a unique mechanism by which certain molecules can drastically enhance the umami flavor – the savory taste often associated with protein-rich foods such as meat, cheese and seafood. Other research has been conducted recently investigating the impact of umami flavor on appetite and subsequent satiety.