Nature's Bounty: Yum's the Word

It's being hailed as a magical new flavor—meaty, complex, savory. Chefs in America and Europe are outdoing each other to show it off. It's versatile. It comes in a variety of shapes and colors. And it can even swim. It's umami, and although it's the latest food phenom, it has actually been around as long as humans have. Now recognized as one of the five basic tastes, umami is likely no newer than its better-known cousins: salty, sweet, bitter, and sour. In fact, experts say, the ability to recognize it in food was vital to the survival of our earliest ancestors. Yet only recently has our culture begun to grasp its importance at the table—and at the bank.

Umami occurs naturally in anchovies—the secret ingredient in Worcestershire and many other sauces—Parmesan cheese, soy sauce, asparagus, and a host of other edibles. These savory ingredients, long relied upon to add pep to dishes, deliver a particular punch to taste receptors because they all contain the molecule L-glutamate. Umami-rich tidbits boost the flavor of any foods they accompany. But they don't receive much credit, probably because they don't drown out the food's own taste. Rarely does one declare a Caesar salad's smashed fish exquisite—yet it's those little swimmers that give the greens their oomph.

Just as a bitter taste is thought to signal the possible presence of toxins in foods, sweetness to alert us energy density, and saltiness to ensure consumption of electrolytes, umami has a purpose: It tips off our tongues to the presence of amino acids in foods, the building blocks of protein. And by upping the savoriness quotient of such foods, it motivates us to take them in. While there's no shortage of protein on supermarket shelves, that has not always been the case, and it still isn't in much of the world. The ability to detect and consume sufficient protein was once integral to our health and growth.

Ancient as the umami taste is, the term "umami" was coined only a hundred years ago, when Japanese researcher Kikunae Ikeda figured there was something quite particular to savory foods. Into his lab he took kombu, a type of seaweed that flavors many soups in Japanese cuisine, and found that the glutamate molecule was the source of its tastiness. But we've been happily chowing glutamate-infused goodies since long before Ikeda was born. The Romans had their noble garum, a prized condiment derived from anchovies that were naturally crushed and fermented at the bottom of barrels of the plentiful food fish. Human breast milk is also rich in umami.

One reason umami is only now getting serious culinary attention is that the flavor rarely exists on its own. You might catch the kids sneaking spoonfuls of sugar, but you probably won't find them stuffing glutamate crystals in their face. In fact, all the taste exemplars—sodium for salty, quinine for bitter, even acid for sour, as well as sugar for sweetness—are palatable on their own. But glutamate tastes slightly unpleasant by itself.

The best known—or most notorious—incarnation of the umami taste is probably MSG, or monosodium glutamate, a flavor enhancer in crystal form produced by fermentation of carbohydrates by bacteria. Although stocked in kitchens around the globe, and especially in Asia, the seasoning has earned a bad-boy reputation in the U.S. as the cause of "Chinese restaurant syndrome." Many experts have found that MSG—first patented by Ikeda—does not cause the headaches and other ills often attributed to it; still, the stigma persists.

Surprisingly, our understanding of taste perception is in its infancy. Barely a decade ago did experts first identify the mechanics of specialized chemoreceptors in the mouth. Despite our attachment to dessert, it took researchers 40 years to deconstruct sweet signaling, says Gary Beauchamp, director of Monell Chemical Senses Center in Philadelphia. Whereas sweet foods latch on to and stimulate their dedicated receptors at many points, salty ones work more pointedly: The sodium molecule fits only into a particular location in the receptor. Umami works more like the sweet spots.

But umami receptors are not confined to the mouth, researchers now find. There's good evidence that umami detectors also exist in the gut, Beauchamp reports. It's likely the job of the tongue-based receptors to recognize the umami flavor and cue us—"glutamate detected, dig in"—while those in the stomach advise the body to begin engaging the protein-digestion machinery.

Glutamate, however, is just one type of amino acid. As neuroscientist Charles Zuker of Columbia University explains, today's umami receptor probably began as a more broadly tuned protein detector. Over time, the cell began to specialize; it went from identifying 20 amino acids to recognizing just one or two. Our bodies kept responding positively despite the narrowing scope of the cell because amino acids come bundled together anyway.

Given our inborn appreciation for them, umami foods are an easy sell. In 2009, the first Umami Burger opened in Los Angeles. The chef capitalizes on our glutamate lust by packing each bite with Parmesan, mushroom, tomato, and other umami-based flavor boosters. Two years later, five locations are booming.

Renowned chef Heston Blumenthal, owner of England's triple-Michelin-starred Fat Duck restaurant, accents many of his dishes with cheese, anchovies, seaweed, and scallops—umami-packed foods all. "Umami is basically a taste that all human beings have but that many just do not recognize. It is a subject very close to my heart," Blumenthal says. Much of the appeal of pizza, he points out, comes from the combination of two naturally umami-rich foods—cheese and tomatoes.

Umami buzz has prompted soy-sauce maker Kikkoman to rebrand itself more, well, umami-ly. Kikkoman is umami. Umami is Kikkoman, the slogan now declares. "Umami is a Japanese term meaning delicious," its ads explain. And they're obviously working: Soy sauce sales are way up.

The umami receptor was once essential, says Zuker. "We don't need it anymore because we go to the supermarket."

Tell that to worshippers of eggplant parmesan or the owner of Umami Burger. If glutamate detection is no longer needed to guarantee health and growth, it's certainly still vital to great taste.

Savory Secrets

Though umami may seem foreign to uninitiated Americans, it permeates many everyday foods. These are some:

• cheese, especially aged Parmesan and aged Gouda
• tomato, especially near the seeds
• fish and fish sauce
• asparagus
• soy sauce
• potato
• sauerkraut
• mushroom
• seaweed
• miso
• pickle
• green peas
• corn