Taste: Surprising Stories and Science About Why Food Tastes Good (48 page)

Lubricious

Viscous

Greasy

Oily

Creamy

Unctuous

Luscious

Slick

I didn’t hate the fat-free stuff as much as most people, because I’m somewhat deficient in fatty mouthfeel perception. I like ice cream but it doesn’t affect me as it does Roger, whose fat tooth baffles me. He’ll pour butter all over everything (if I’m not around), drink pints of his homemade eggnog at holiday time, and eat pounds of white-striped Kobe beef. My trigeminal nerve damage has negatively affected my appreciation for superfatty foods. I’m envious of Roger’s enjoyment of hollandaise and clearly am not getting the same something. We differ tremendously in our ability to appreciate fat’s contribution to texture, but studies trying to correlate PROP tasting ability (for example, being a HyperTaster) with fat tasting ability show mixed results.

The best argument for a fat taste is that those poor taste-blind mice (with the severed taste nerves) stopped choosing calorie-rich fatty food when they couldn’t taste the difference between it and regular mouse chow. Stimulating the taste system stimulates digestion, and that is why we have taste cells in our esophagus and gut as well as our mouth: to start revving the system into gear when food is on its way. This is known as the
cephalic phase of digestion
, which happens before food even enters your mouth.

We need fatty acids for nutrition, but if you were to chemically separate the fatty acids from the oil or solid fat, you’d get a substance that tastes horrible to 30 to 45 percent of the population. But even the sensitive fat tasters didn’t have any better way to describe it than “yuck.” This, says Mattes, is another argument for why we have the ability to taste fat. The icky taste of fatty acids may be akin to the unpleasantness of bitter; both function as warning signals. Tasting a yucky free fatty acid communicates to us that the fat is rancid and should not be eaten.

But rancidity is detectable by aroma, too. So why would we need to taste it if we can smell it? Again, we don’t know yet. Our taste for fat is a hot topic for research, as is our taste for other things such as calcium.

Salt makes food come alive, but Americans eat twice as much salt as we need. Could our collective craving for salty food perhaps be a misplaced craving for something else? Could we be forgiven for ordering a glass of salty tomato juice to wash down our salty snack mix? (And why, for that matter, do people drink more salty tomato juice at 30,000 feet than at sea level? Think about it. At what elevation did you last order a bloody Mary?)

Monell’s Michael Tordoff believes that when we reach for salty foods, we may actually be craving calcium. There are two forms of calcium in the blood, a free form and a bound form. The free calcium is the kind that’s important for human nutrition. Eating salt frees the bound calcium and makes it more available to the body. If you eat a low-calcium diet, you’ll feel better immediately following a salty meal, having freed some of the bound calcium in your body.

Tordoff’s research has shown that calcium-deficient women tend to prefer saltier food than those who consume enough calcium. Tordoff also believes that we need to add calcium to the list of Basic Tastes. His team discovered that mice
have two calcium taste genes. We don’t yet know if this holds true for humans. “But it seems pretty likely we have the same function,” Tordoff says.

Ajinomoto, the Japanese company that introduced the world to powdered MSG, has continued to do extensive research on taste, constantly looking for the next great taste enhancer. They recently found that the calcium-sensing receptor can make the Basic Tastes of sweet, salt, and umami savor more intensely. This could explain why we evolved to have calcium receptors: to make calcium-rich food taste better so we’ll eat more of it.

If you want to experience the taste of calcium, you have a few options. You could buy some white chalk at an art-supply store, plug your nose, and lick it—that’s pure calcium carbonate (one of the many forms of calcium). You can buy calcium capsules at a health food store, open one up, dump out its contents, stick your finger in, and taste the calcium. What will you experience? I like to use the descriptive term for the taste coined by Tordoff:
calci-yummy.

Altitude sickness is a strange affliction. It seems to attack its victims randomly; if you are struck by it once—or even if you’re not—there’s no telling if you’ll get it the next time you’re at a high elevation. The best thing you can do to avoid the debilitating headaches, nausea, fatigue, and worse symptoms is to be proactive and take acetazolamide, also known as Diamox, considered one of the best preventive measures when used along with acclimation and a healthy constitution.

In the 1980s, Stephen Kelleher took acetazolamide and a six-pack of beer up a mountain to celebrate his summitting. When he got to the top he was disappointed to find that the beer tasted “like dishwater.” I’d be more likely to carry a bottle of Champagne, but regardless of the type of bubbly beverage you carry to the top of a mountain, you’ll be disappointed in its taste if you’ve taken medicine to prevent altitude sickness. The drug blocks an enzyme that helps detect carbon dioxide, or CO
₂
. Kelleher concluded, “Mountaineers must choose to leave either their acetazolamide, or their suds, at home.” The beer-drinking doctor called this “the Champagne blues.”

Research into the Champagne blues led to the realization that we may
taste
carbonation as much as we feel it. The same taste receptor cells that detect sourness also detect CO
₂
. The scientists who identified this wrote:

Although CO
₂
activates the sour-sensing cells, it does not simply taste sour to humans. CO
₂
(like acid) acts not only on the taste system but also in other (ways), the final percept of carbonation is likely to be a combination of multiple sensory inputs. Nonetheless, the “fizz” and “tingle” of heavily carbonated water is often likened to mild acid stimulation of the tongue, and in some cultures seltzer is even named for its salient sour taste.

They pointed out that seltzer in German is called
sauer Sprudel
or
Sauerwasser
, both translated as “sour water.”

When I came upon a product called Fizzy Fruit at a trade show years ago, I admired the innovation of infusing CO
₂
gas into fruit the same way it’s infused into water to make carbonated drinks. The inventors perhaps believed that by adding a unique sensory element to grapes, for example, they could entice kids to eat fruit in lieu of more hedonically appealing, but less nutritionally beneficial, candy. The first time I tried Fizzy Fruit, however, I recoiled instinctively. It just tasted
wrong.
Later I realized that it reminded me of old orange juice that had begun to ferment. We may have evolved to taste CO
₂
so we can detect the fizz of fermentation where it doesn’t belong, in spoiled foods like orange juice or tomato sauce that’s been around too long. In addition to providing a biological reason for the need to taste carbonation, this may also explain why Fizzy Fruit hasn’t exactly overtaken the market for candy.

Recognizing Basic Tastes is somewhat akin to recognizing primary colors. There are many colors in the spectrum, but all are made up of some combination of red, yellow, and blue. When you look at green you don’t usually think,
That’s a combination of 75.3 percent yellow and 24.7 percent blue.
You simply think it’s green. Because you synthesize things you see, vision is considered a synthetic sense: the inputs come together in your mind as one coherent perception instead of as parts.

Our sense of smell is also considered a synthetic sense. When you experience a bunch of aromas, you fuse them all together and they become “a tomato” or “a banana,” or “McDonald’s.” You’d be hard-pressed to pick out the individual aroma compounds, even if you know the smell intimately.

Taste, on the other hand, can be considered an analytic sense because we are able to analyze the Basic Tastes in a mixture. Complex aromas are more difficult
to analyze. You can easily say that a tomato is sour and sweet, but you have to be trained to identify its aroma compounds.

There are countless flavors in the world, made up of a combination of the five Basic Tastes, countless aromas, and a countless variety of textures. My food-developer definition of a Basic Taste is that which we detect using our tongue alone—like salt—without the benefit of any other sense. The problem arises when scientists are faced with
something
unique that isn’t sweet, sour, bitter, salt, or umami. Take water, for example. Certainly water has a taste. When you remove all of the minerals that contribute flavor to waters such as Evian, you’re left with a liquid that isn’t sweet, sour, bitter, salt, or umami. So what exactly is the taste of water? If we don’t have a word for it, but we can detect it with our sense of taste, should we consider it a Basic Taste?

Another definition of what constitutes a Basic Taste is any taste for which we have a receptor on our tongue. With this as part of his definition, Monell’s Paul Breslin says, “There might be around twenty qualities of taste but I am most comfortable saying that there’s five.”

Twenty Basic Tastes? While this may sound preposterous now, the field is still new enough that we simply can’t say there are only five Basic Tastes
for sure.
Some people argue that the effort to anoint Basic Tastes is frivolous, but I disagree. The five points of the Taste Star help me think about food in a structured way. I use it to make foods taste better. Most people can detect five tastes and I hope my explanations of them help you think about taste when you’re eating or cooking. The Taste Star is a useful concept outside the scientific debate, which is where most of us live and eat.

Top Contenders for Induction into the Basic Taste Hall of Fame

*
I believe umami belongs in the “Accepted” column, but because there are enough scientists who disagree with me, I feel compelled to include it here.