Food scientist directs Rutgers’ Sensory Evaluation Laboratory
By: Pat Tanner
It seemed like a good idea at the time but when the day came to be tested, I had serious misgivings.
I had met Beverly Tepper, Ph.D., director of Rutgers University’s Sensory Evaluation Laboratory in New Brunswick, socially, through mutual friends, and when I learned that her area of research involved taste perception, I thought it only natural fun, even to offer myself as a test subject, and subsequently to report in this space on where I fall on a scientific scale that measures, in effect, the sensitivity of one’s taste buds.
But as the appointed hour approached, I began to fret. Where would I test out along the spectrum of supertasters, tasters and nontasters? I wouldn’t mind being either of the first two (or so I thought), but what if I, a Packet food writer and the restaurant critic for New Jersey Life magazine, had to confess in print to being a nontaster? Not a smart move, career-wise.
Dr. Tepper and her staff use a compound called PROP (pronounced "prope" and short for 6-n-propylthiouracil) to effectively measure the ability or non-ability to taste bitterness. It turns out that perception of bitterness is a genetically based indication of how sensitive a person is to a whole range of tastes, including sweet, fat and spiciness. Research indicates that supertasters those whose sensitivity to bitter is highest also have more taste buds.
So supertaster is what I wanted to be, or so I thought until I sat down with Dr. Tepper in her office. Supertasters, it turns out, typically dislike a lot of foods, in part because they experience them so intensely. A typical supertaster dislikes the bitterness of cruciferous vegetables like broccoli and Brussels sprouts, for example, and dishes with hot chile pepper not the best qualifications for a food critic.
Where people fall depends on their response when a small circle of paper embedded with the PROP compound is placed on their tongues for a few seconds. Supertasters experience an overwhelmingly unpleasant, acrid sensation. Tasters detect some bitterness, but not to the same get-this-abomination-off-my-tongue degree. Nontasters wonder what all the fuss is about, since they detect nothing at all.
"I’m a supertaster myself," Dr. Tepper explains, "and I should hate strong and spicy foods but I like them." She has come to realize that supertasters fall into two behavioral categories, those who are adventurous eaters and those who are not. "I like those foods because I gave myself the opportunity to try them over and over," she says.
Like Dr. Tepper, I also am an adventurous eater there are few foods I dislike categorically and my theory is that given the inclination, adventurous supertasters probably enjoy the intensity the frisson of pushing the limits of their sensitive taste buds. At least, this is what I told myself before taking the test, in hopes of being one myself.
Dr. Tepper said that that research on bitterness indicators, which has been going on since the 1930s, has consistently shown that 25 percent of Caucasians are nontasters, 50 percent are tasters and the remaining 25 percent are supertasters.
"Other ethnic groups have different breakdowns," she informs me. "The split around the world is quite different. Take chile pepper, for example. The hypothesis is that tasters and supertasters should not like chile pepper. But in Korea and China, where they have very few nontasters and almost everyone is a taster, they like chile pepper! So how much of a role can genetics be playing in them?" she asks.
In fact, it is the marrying of genetics with people’s personal histories and behaviors that most interests the food scientist in Beverly Tepper, who got her Ph.D. at Tufts University, where she was a member of the first class in the school of nutrition. While doing post-doc work at the Monell Chemical Senses Center in Philadelphia, she became interested in the science of taste. "Then, in 1989 there was an opening for a sensory scientist at Rutgers most food science departments have one and I have been here ever since," she explains.
Dr. Tepper is a recognized expert in the area of food selection and dietary habits, with many years of experience studying consumer behavior.
"I’m a basic research scientist," she says. "I’m interested in how people’s tastes vary how they react to different tastes, how to explain the differences in people’s appreciation of tastes, and how to use this information in a clinical health setting. We can test behaviorally that is the foundation. But then we have all our life experiences, which can moderate the effect of that gene on our behavior. In our lab, we do our own research and we work with other food science departments on sensory assistance. We work with industry, as well."
Clients include food, beverage and personal care companies, and her lab helped launch "Jersey Blues," the blueberry-flavored iced tea that is produced in cooperation with the New Jersey Agricultural Experiment Station.
But what purpose, practically speaking, does it serve to know if a person is a supertaster or not?
"Looking into the future, I see a possible application of my work in the study of one of the most pressing issues in American health today: obesity," Dr. Tepper says. She has conducted a study that confirmed that people with Type 2 diabetes have an increased desire for sweets, and recently has been focusing on women with gestational diabetes.
"How to understand the best dietary treatments; who does better on what type of diet; can we individually link a person to a certain diet based on their taste preferences, which may be genetically determined, to make the most of them?"
Her research program combines food sensory science with nutrition science and psychology to answer these questions.
Current projects include exploring the relationship between PROP status as a marker for dietary fat preference and body weight in children and adults. One study she cited found that supertasters seem to experience "creaminess" in dairy products more than nontasters, the implication being that nontasters may prefer higher fat than supertasters or need more of it to achieve the same level of satisfaction. Supertasters are also more sensitive to both the sweetness and the bitter aftertaste of saccharine.
"I have a theory," she muses. "I can’t prove it, but I think the people who call 800 numbers to complain about a (food) product are supertasters."
In another study, Dr. Tepper compared the body-mass index (BMI) of a group of middle-aged women who were classified by their PROP status. "Nontasters were the heaviest and supertasters the lightest," she reports.
Learning all of this did little to ease my tension as she and I walked down the hall to her lab, which includes a fully equipped kitchen and a row of 11 white tasting booths. She asked how I was going to interpret the results of my own PROP testing.
"If you are a nontaster, it’s OK: You can be happier, you won’t be bothered by all the qualities that bother supertasters," she assures me, then continues, "being a taster or not has no bearing on flavor detection," referring to the fact that the vast majority of flavors we perceive come through our noses, and that PROP measures sensitivity only to the basic sensations of sweet, sour, salty and bitter. (Some would add a fifth sensation, that of savory, sometimes called "umami.")
"Detecting odors is a distinct anatomical function," she adds, to little avail.
It took just a few moments in the testing booth, and a couple of paper discs on my tongue, before I got the results. I am, in fact, a supertaster. Just what I wanted to hear, at least going into this. Now, it wasn’t so clear. Since then I have rationalized the result this way: I fall, obviously, into the category of adventurous supertaster; I am able to describe clearly the intense sensations I experience while eating, and I don’t need mass quantities of food to do so.
That’s my story, at least and I’m sticking to it.

