The historically unappreciated taste is produced by two interacting sets of molecules, each of which is needed to trigger cellular receptors on your tongue's surface.
"This opens the door to designing better, more potent and more selective umami enhancers," said Xiaodong Li, a chemist at San Diego-based food-additive company Senomyx.
Four other basic tastes -- bitter, sweet, salty and sour -- were identified 2,400 years ago by the Greek philosopher Democritus, and became central to the western gastronomic canon.
In the late 19th century, French chef and veal-stock inventor Auguste Escoffier suggested that a fifth taste was responsible for his mouth-watering brew. Though Escoffier's dishes were popular, his theories were dismissed until 1908, when Japanese chemist Kikunae Ikeda showed that an amino acid called glutamate underlies the taste of a hearty variety of seaweed soup.
In honor of Ikeda, the taste was dubbed umami, the Japanese word for delicious. It took another 80 years for umami to be recognized by science as comparable to the other four tastes.
In the meantime, monosodium glutamate became wildly popular as a flavor enhancer. But MSG can cause headaches and dizziness, and has been tenuously linked to long-term neurological disorders.
"The only way to have a substitute is to find the molecular target of glutamate. If we figure that out, then we can screen for agents that are not glutamate but could mimic it," said Johns Hopkins University neuroscientist Solomon Snyder, who was not involved in the new study.
Li's team have taken human kidney cells and added the genes for receptors linked to umami taste. Receptors form on the cells' surface, geometrically resembling the mouth of a Venus flytrap. When glutamate is caught on a receptor's lips and a molecule called ribonucleotide lodged in its throat, the receptor snaps shut.
"The configuration of the receptor changes, sending a signal down into the cell," said Li. In their engineered and disconnected cells the signal quickly fizzled -- but in a tongue surface cell, said Li, "Your brain gets a signal: Something tastes good that is in my mouth." The four basic tastes -- sweet, sour, salty and bitter -- you were taught in grade school were actually incomplete. Your tongue can also taste a fifth basic taste: umami.
Umami is the taste of glutamate, which is a savory flavor found in many Japanese foods, bacon and also the toxic food additive MSG. It is because of umami that foods with MSG taste heartier, more robust and generally better to a lot of people than foods without it.
Despite its ability to enhance flavor, MSG is one of the worst food additives on the market. It is an excitotoxin, which means that it overexcites your cells to the point of damage, acting as a poison.
Fortunately, people are catching on to its dangers, and as such are trying to avoid foods that contain MSG. This is where the food-additive company Senomyx, which employs the chemist who co-authored the above study, comes in.
They are in the business of creating food chemicals and manipulating your taste buds, and are likely hoping to one day develop a chemical that will activate your umami taste receptors.
The company has already developed several chemicals that, although they contain no flavor of their own, activate or block receptors in your mouth that taste. The chemicals can mimic or enhance savory, sweet and salty tastes, and are intended to reduce the use of sugar, salt and MSG in processed foods.
One of Senomyx’s chemicals even causes a “cooling” taste, and we have only just begun to hear about the “innovations” that come from this company.
Senomyx already has 119 patents, and 389 more pending, in the United States, Europe and elsewhere in the world.
You Won’t Know Whether Senomyx’s Chemicals are in Your Food
While at first glance it may seem like a positive step to create processed foods with less sugar, salt or MSG, keep in mind that this is being done with synthetic chemicals.
Senomyx was able to obtain FDA approval and a “generally recognized as safe” classification from the Flavor and Extract Manufacturers Association in less than a year and a half, based on a safety study of rats conducted for just 3 months.
That’s right: one three-month long study is apparently enough for major food manufacturers to decide that a never-before-used chemical is safe for you and your family to eat.
And these chemical compounds are NOT required to be listed separately on food labels; they are simply grouped into the general category of "artificial flavors." So if you pick up a processed food that has “no MSG,” “less sugar,” or “reduced sodium” it may very well also contain Senomyx’s chemicals, and you’ll have no way of knowing.
Senomyx has entered into collaborations with the following food and beverage companies:
• Ajinomoto Co
• Campbell Soup Company
• The Coca-Cola Company
• Firmenich SA
• Campbell Soup Company
• The Coca-Cola Company
• Firmenich SA
So far, Nestle has already begun adding a savory flavor enhancer to some of its bouillon products. And Coca-Cola and Cadbury are planning to begin using Senomyx’s compounds in early 2009.
When it comes to adding synthetic substances like this it would seem obvious that the best strategy is guilty till proven innocent, a variation of the precautionary principle.
I suspect it is relatively harmless in small quantities for most but it is hard to imagine it not moving nearly everyone to some ill health or disease if they regularly used it.
Just Another Reason to Limit Processed Foods
Flavor enhancers that manipulate your taste buds are just one more reason to return your diet to whole, unprocessed foods -- preferably organic and biodynamically grown and locally harvested. Real foods have flavors that your taste buds won’t want to miss, and if you want to add less salt to your homemade soup or stew, or cut the sugar out of your favorite healthy dessert, you can do so without having to replace it with a mystery chemical.
Although it does take a bit more planning and time in the kitchen, preparing food at home, using fresh, locally grown ingredients, will give you better flavor and more health value than any processed food that you could buy at your supermarket.