It was discovered more than a century ago and is best described as having a salty or “meaty” flavor. The word “umami” is Japanese and means “a tasty and pleasant taste”. The umami flavor can be found widely in a large number of foods, so you don't need to go to a specialty store to enjoy the taste of umami. Foods with umami elements that can be found at the local supermarket include beef, pork, sauces, broths, tomatoes, cheese and soy sauce.
Fermented foods such as fish sauce and miso are especially rich in umami flavor. Part of the traditional Japanese diet consists of a simple soup broth made with seaweed and perhaps a fish component. And it gives it a very tasty flavor, which is quite pure. It's the basis of many Japanese foods; you see it in things like soy sauce.
Humans literally learn to appreciate umami from day one. Breast milk contains a large amount of glutamate, as does amniotic fluid. We also look for it later in life, usually without even knowing it. The Umami Information Center has a list of the foods richest in umami.
Tomatoes (especially sun-dried tomatoes), Parmigiano cheese, anchovies, cured ham, seaweed, mushrooms, and cultivated and fermented foods (especially cheese and soy, fish and Worcestershire sauces) top the list. You can taste umami in foods that contain a high level of the amino acid glutamate, such as Parmesan cheese, seaweed, miso and mushrooms. One of the reasons it is so commonly found in aged and fermented foods is that, as foods age, the proteins they contain break down, releasing amino acids through a process called proteolysis, which increases their level of free glutamates. And while there's nothing wrong with preparing a dish with a little bit of MSG, much of Chinese food is already naturally high in glutamate, inosinate and guanylate, thanks to the abundance of ham, shiitake mushrooms and seafood.
Some umami-rich foods, such as kombu seaweed or Vegemite or Marmite yeast extracts, may be a little harder to find if there isn't a specialty market nearby. So, by adding MSG to foods, you don't just get this flavor component; I think you add a sensation component. Parmesan, especially parmesan that has been aged for a long time, is the only food, other than algae, that can compete with the levels of glutamate found in sun-dried tomatoes. Umami has become popular as a flavor among food manufacturers trying to improve the flavor of low-sodium products.
Anjimoto, the company founded by Ikeda, sells pure monosodium glutamate, which is a natural product that acts as a flavor enhancer similar to adding salt to a dish. Foods rich in umami are naturally found in a diverse set of ingredients ranging from Parmesan cheese to tomatoes, aged beef and kombu, which are algae used to make dashi. It is a word that is present throughout the culinary world today; from jar labels to hamburger chains, everyone talks about the amount of umami in their food. The idea that there was a different flavor was based on the discovery that the pure sodium salt of monosodium glutamate, which is the most common amino acid in the body, has a different flavor that is characteristic of the flavor, and that it tastes different from sweetness, is different from acid, is different from salty and is different from bitterness.