The Science Behind Umami

If someone asked you to explain why your best friend is so special, you might point to their personality or your shared hobbies. Yet, there's something about how all these traits come together, a unique chemistry between you two, that defines your bond.

To understand why foods like cheeseburgers, ramen, and lasagna are so irresistible, it's time to explore umami—the mysterious chemical and flavor connection that ties tastes together.

Umami (pronounced oo-MAH-mee) is recognized as the fifth basic taste, complementing the classic four: salty, sweet, bitter, and sour. The term 'umami' comes from the Japanese word 'umai,' which roughly means 'deliciousness' [source: Umami Information Center]. Chefs have described it in various ways, ranging from 'delicate and subtle' to 'earthy, musty, and mushroom-like' [source: Ninomiya]. For many, the sensation is simply irresistible [source: Souza].

For food scientists, umami represents literal chemistry. Like the other tastes, umami serves as a biological message, and by deciphering it, researchers uncover more about the physiological aspects of taste. The discoveries could have significant implications for human health, evolution, and the food industry's economic prospects. Umami is also a key element in crafting deeply satisfying meals.

So what exactly is this subtly earthy, delicately musty deliciousness that has captured the attention of scientists, food creators, and everyday food lovers alike? Continue reading to discover how one man's fascination with a particular food item set the stage for uncovering this flavor phenomenon.

The Discovery of Umami

Humans have enjoyed umami for millennia, even before it was officially recognized. For example, two thousand years ago, the Romans savored garum, a sauce made by fermenting fish until it became a liquid [source: Koetke].

The breakthrough in recognizing umami as a distinct taste occurred in 1907 when Kikunae Ikeda sought to uncover the mystery of dashi [source: Koetke]. Dashi, a key element of Japanese cuisine, is a fish stock made by simmering dried bonito flakes, a type of tuna, in a kelp-based broth, known as kombu. It's an essential ingredient in many traditional dishes, including miso soup (crafted from fermented soybean paste) and sauces for buckwheat soba noodles and tempura vegetables [source: Wang]. While studying in Germany, Ikeda realized that dashi shared the same rich savoriness found in tomatoes, asparagus, and other foods [source: Ninomiya]. This distinct flavor experience would later become known as umami.

Ikeda wasn’t just a culinary enthusiast; by the time he began his research, he was a chemistry professor at the Imperial University of Tokyo. His first step was to chemically analyze dried kelp. Using water extraction and crystallization, he meticulously isolated and identified its various components. He found several salts, including potassium chloride and sodium chloride (table salt) [source: Lindemann]. However, as both a chemist and a lover of dashi, Ikeda was certain these weren’t responsible for the umami flavor. Eventually, he identified the compound that matched both the taste and chemical properties: monosodium glutamate (MSG) [source: Kenzo]. MSG, as the name implies, is a sodium salt derived from glutamic acid, an amino acid that serves as the building block of proteins.

A few years later, one of Ikeda's students discovered that the main umami component in dried bonito was inosinate. Inosinate is a type of protein known as a nucleotide [source: Kenzo]. Around 1960, scientist Akira Kuninaka identified guanylate, another nucleotide found in shiitake mushrooms, as a third contributor to umami. More importantly, Kuninaka showed that the interplay between these three elements is synergistic: They work together to amplify the umami effect dramatically [source: Ninomiya].

This is the history of umami. To fully grasp how it enhances the flavor of food, let’s take a brief dive into taste physiology—a journey through the tongue and beyond.

The Science of Taste

If it's been some time since your last science class, here's a quick refresher: Looking at your tongue, you'll notice its surface is covered in hundreds of small, rough bumps known as papillae. Each of these papillae houses taste buds. Some papillae contain only a few buds, while others may have hundreds. These taste buds are not evenly distributed, with fewer located on the throat and roof of the mouth as well [source: Monell].

Taste buds act as the connection between the tongue and the brain. They are equipped with receptor cells, where the chemical reactions that result in taste perception occur [source: National Library of Medicine]. Just as papillae contain varying numbers of taste buds, the buds themselves contain varying numbers of receptor cells, ranging from just one to as many as 700 [source: Monell]. These specialized cells are genetically programmed to communicate a single taste sensation each [source: Roth-Johnson].

The process of taste begins when a food (or any substance) enters the mouth. Once inside, it's broken down through chewing and dissolved in saliva, which then coats the taste buds with the substance's chemical compounds. Using different mechanisms (which we'll discuss later), the receptor cell walls convert these chemicals into electrical signals, a process called transduction. Nearby nerves transmit these impulses to the nucleus of the solitary tract (NST) in the brain, where the signals are compiled into a message identifying the taste.

Taste is the first factor in determining whether something in your mouth is safe to consume. However, deciding whether to eat it goes beyond taste alone. It's about flavor. Flavor is a multisensory experience that combines not just taste, but also aroma, texture, temperature, intensity, and even the memories or emotions the food may trigger. Processing all this information involves several higher-function areas of the brain [source: Monell].

That's the basic pathway by which food in your mouth becomes taste in your brain. Now, let's explore the unique mechanisms of umami.

How You Taste Umami

The way umami signals to the brain differs slightly from other tastes, starting with its receptor cells. The cells that respond to sweet, bitter, and umami tastes are known as G protein-coupled receptors (GPCRs). In contrast, sour and salty tastes are believed to travel through ion channels that involve charged molecules [source: Monell].

Three types of receptor cells are known to respond to the combination of inosinate, guanylate, and MSG, though others may exist. It's suggested that these receptors not only detect these compounds but also 'hold on' to them longer than receptors for other tastes [source: Marcus]. This may explain why umami has the ability to enhance the nuances of other flavors, making a sweet dish not just sweeter but differently sweet. Picture apple pie with cheese, prosciutto-wrapped figs, or chocolate-covered bacon.

One lingering question is about the evolutionary purpose of umami. It's widely believed that before humans understood the concepts of health or nutrition, taste was a survival guide, indicating which foods were safe to eat and which could be harmful. Sweet tastes, for instance, signal the presence of fruits and vegetables that provide essential carbohydrates and vitamins. Umami, on the other hand, is a signal for proteins, which are critical nutrients. Interestingly, the amino acid most associated with umami, glutamate, is something the human body can easily produce [source: Geiling].

However, other proteins not naturally produced by the body are equally vital, known as essential proteins. These must be included in the diet because the body cannot synthesize them. While protein itself has no flavor, it's the amino acids that are released from the protein molecule during processes like cooking, drying, and fermenting that are detected by taste buds [source: Koetke].

When amino acids are freed, it also initiates their digestion and metabolization in the body. Some anthropologists argue that this is one reason why humans have outpaced other species in terms of brain development. Cooking speeds up the breakdown and digestion of amino acids and other nutrients, facilitating rapid brain development in humans [source: Kiger].

The food industry has long understood the financial benefits of incorporating umami. Keep reading to discover how it’s making its way into everything from fast food to fine dining.

Umami in the Food Industry

Kikunae Ikeda, the scientist who discovered umami, quickly capitalized on his groundbreaking finding. In 1909, just a year after identifying monosodium glutamate, he collaborated with an iodine processor to patent a commercial MSG-based seasoning, along with a method to extract MSG from wheat—a more abundant source of glutamic acid than seaweed. His aim was to provide an easy way to enhance the flavor of wholesome but bland homemade meals, thereby improving the health of the Japanese population [source: Ninomiya]. Ironically, MSG, once considered a health-enhancing ingredient, is now often associated with junk food and unhealthy eating.

Umami compounds are widely used in the food industry for their ability to amplify other flavors and create depth and texture, earning them the reputation of being "flavor potentiators" [source: Souza]. In addition to MSG, other industrially prepared sources include hydrolyzed wheat protein, texturized vegetable protein, and autolyzed yeast extract [source: Marcus]. Although these are natural substances, they may also be manufactured in laboratories, leading to MSG being listed as "natural flavors" on ingredient labels [source: Yacoubou].

These same properties make umami particularly valuable in improving the nutritional profiles of processed foods. As a flavor enhancer, it can reduce the need for less healthy ingredients. Moreover, when produced with potassium chloride instead of sodium chloride, it can help lower sodium content in certain foods. Its savory, meaty qualities create a fuller mouthfeel, which can make low-fat foods feel more satisfying and filling to consume [source: Marcus].

The benefits of umami can be especially useful for older adults who often experience a decline in their sense of taste and smell, as well as for those undergoing treatments or taking medications that damage sensory cells [source: Marcus].

In addition to its health applications, umami is also one of the most sought-after trends among innovative chefs and their customers. The gourmet hamburger chain Umami Burger, for example, is named after the taste and incorporates it by adding powdered mushrooms and seaweed to its beef patties and topping the burgers with soy sauce [source: Geiling].

The kitchen at home also offers plenty of opportunities to incorporate umami. To conclude this exploration, here are some ideas to inspire your culinary imagination.

Discovering how to incorporate umami into recipes can be an exciting culinary adventure. Click here to explore some tips on adding this rich flavor to your meals.

Umami’s presence in global cuisine is undeniable. From Denmark’s smorrebrod (an open-faced sandwich with roast beef and pickles on sourdough rye) to the classic American BLT, umami is everywhere. Here are a few culinary tips to enhance your dishes and bring out more of this savory taste:

By learning to cultivate umami in your cooking, you not only enhance your dishes but also expand your culinary abilities. In a way, you're creating your own unique umami: the skill to draw out and amplify the natural flavors in food.