Umami: The 5th Taste

Being able to distinguish the umami taste takes some practice because it's not as obvious as other tastes, such as sweet or bitter. For example, when tasting a homemade chicken broth made without salt or seasoning of any kind, you may find it bland and practically tasteless. If you added a small amount of monosodium glutamate to that same broth, the umami taste it provides may lead you to describe the "enhanced" broth as tasting "more like chicken" than the first broth. This taste is not as simple as making something taste more salty (salt alone can do that). Rather, the umami taste is one of richness, fullness and complexity. Simply put, it just makes the food taste more delicious.

Glutamate's the key
The amino acid glutamate could well be called "nature's flavor enhancer" because it conveys the umami taste in foods. Glutamate is also well known among food and nutrition professionals as one of the most common "building blocks" of protein. As such, it's no surprise that most foods contain some amount of glutamate. Protein foods, such as meat, fish, cheese, milk and some vegetables are especially good sources of glutamate. Not coincidentally, these foods also have a lot of umami taste.

Source: Inaba. A. Yamamoto, T., Ito, T., Nakamura, R. Changes in the concentrations of free amino acids and soluble nucleotides in attached and detached tomato fruits during ripening. J. Japan Soc. Hort. Sci., 1980, Vol. 29, No.3

In some foods, the amount of glutamate they contain—and their flavor—increases as they age or ripen. For example, according to research, aged ham and aged cheese have much more glutamate than their "younger" counterparts. The graphic to the left illustrates this concept using a ripening tomato. As a tomato ripens from green to red, its glutamate content increases dramatically. The superior flavor of the ripe tomato can be attributed, in part, to its higher glutamate level.

See chart for glutamate content of selected foods

 

 

Adding umami to foods
Over 1,200 years ago, Asian cooks began adding a type of seaweed found in the Pacific Ocean to their soup stocks. They had discovered that foods cooked in this seaweed broth simply tasted better. What these chefs didn't know was that the broth's unique flavor enhancement quality was due to the high levels of naturally occurring glutamate in the seaweed.

Finally, in 1908, the link between glutamate and the seaweed was discovered. A professor at Tokyo Imperial University, Dr. Kikunae Ikeda, isolated glutamate from the seaweed and unlocked the secret of the plant's flavor-enhancing properties. Dr. Ikeda then went on to study various forms of glutamate, trying to find one that conveyed the umami taste and was also practical to produce commercially. He found that the sodium salt form, called monosodium glutamate, fit the bill: it provided umami and was easy for home cooks to use and store.

Monosodium glutamate, often referred to as "MSG", was first produced in Japan in 1909, and made its U.S. debut in 1917. Since then, food manufacturers and home cooks alike have used MSG to augment the flavor of a wide variety of foods.

Recognizing that "Mother Nature" knows best, when food manufacturers add monosodium glutamate to foods, they use it in levels that are comparable to the glutamate levels found in natural foods. Generally, this means only a small amount is used—usually between 0.1% and 0.8% of the food's weight. Home cooks have it easier—there's a "rule of thumb" for how much MSG to use.

You might be surprised to learn that, according to a 1995 U.S. Food and Drug Administration study, some foods naturally contain higher levels of glutamate than those typically added to foods during manufacturing. For example, the natural glutamate level in aged Parmesan cheese was found to be up to 10 times that found in chicken broth with added monosodium glutamate!

Want more information on cooking with monosodium glutamate? Need recipes?

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