Umami: The Most Complex Taste | Serving Up Science

Apr 3, 2019

Most people know the four main senses of taste: sweet, sour, bitter, and salty. But there’s also a fifth sense, which is more complex. Umami.

Umami is what we associate with a savory experience that can be difficult-to-describe. Think of miso soup or seared meats.

The name umami is a term that combines the Japanese characters for delicious and taste.

The discovery dates back to the early 1900’s, when a University of Tokyo scientist named Kikunae Ikeda was thinking about the taste of the kelp based broth kombu dashi. The story goes that he started pondering whether the savoriness of the dish was a biologically determined taste for something he couldn’t quite pin down.

Ikeda was determined to figure out what that “something” actually was, which involved chopping and sampling dried seaweed.

Ikeda figured out that this savory taste was linked to the salt of glutamate - a type of amino acid which we find in many foods. But also that it’s more than a “taste” exactly. It’s a sensation.

Interestingly, were you to sip the salt of glutamate, or a mixture of monosodium glutamate (MSG) for example, in a water solution, it wouldn’t taste like much of anything. So, umami isn’t quite it’s own flavor, rather something that enriches others.

MSG gets a pretty bad rap these days. Robin Tucker is Assistant Professor of Food Science and Human Nutrition at Michigan State University. According to Tucker, people really don’t have much to worry about when it comes to MSG.

“People associated it with some unpleasant symptoms that they had after consuming it. But scientists really haven’t really been able to reproduce those symptoms reliably. So if people think that they are sensitive to MSG, it might not be the MSG itself. It might be something else in the food that they’re eating.” Tucker said.

 

The umami effect is what makes the cheese-and-tomato combination so enjoyable. Both cheese and tomatoes, notably, also contain MSG naturally. The experience involves both taste and aromas, and umami heightens each. However, scientists don’t exactly understand how that happens.

That’s because it works differently than our four “basic” tastes: Sweet, salty, bitter and sour.

 

Those tastes are more clear cut and we know more about why we experience them. Sugars are essential for our bodies, so we crave that sweet taste. And, we need a little bit of salt in small amounts, which tastes good. While a pile of salt doesn’t.

"So if people think that they are sensitive to MSG, it might not be the MSG itself. It might be something else in the food that they're eating." -Robin Tucker, Assistant Professor of Food Science and Human Nutrition at Michigan State University

Both bitterness and sourness can let us know if something we find is toxic or has begun to rot. All of these tastes provide important clues linked to human survival.

Though scientists still haven’t figured out what purpose umami serves, we do know glutamates themselves serve vital roles in human biology. For example, glutamates make it possible for neurons to fire in our brains. They also aid in digestion. They are present in breast milk and umami receptors also line the small intestine.

Tucker explains that the increased prevalence of umami in modern cooking could also help people cut down on their sodium intake:

“Umami has kind of a salty flavor, but it’s a little more complex than that. And you can use MSG instead of salt in cuisine to lower the sodium content of what you’re making. So that’s one potential health benefit.” Tucker said.

While we don’t know why it’s the fifth taste, we do know umami supercharges other flavors. And for most, that’s a good thing.