Ethnicity may play a role in how sensitive a person is to the bitter taste found in for example broccoli, Brussels sprouts, and dark chocolate, researchers say.
By letting test subjects taste the bitter substance PROP, two studies show that Danish and Chinese people experience this basic taste differently.
The reason seems to be related to an anatomical difference upon the tongue surfaces of these two groups.
“Our studies show that the vast majority of Chinese test subjects are more sensitive to bitter tastes than the Danish subjects. We also see a link between the prominence of bitter taste and the number of small bumps, known as papillae, on a person’s tongue,” says Wender Bredie, professor in the food science department at the University of Copenhagen.
On the tip of your tongue
Using an artificial intelligence method, researchers collaborated with Chenhao Wang and Jon Sporring of the University of Copenhagen’s computer science department and analyzed the number of mushroom-shaped “fungiform” papillae on the tongues of 152 test subjects, of whom half were Danish and half Chinese.
Fungiform papillae, located at the tip of the tongue contain a large portion of our taste buds and play a central role in our food and taste experiences. To appreciate the significance of papillae in food preferences across cultures and ethnicities, it is important to learn more about their distribution, size, and quantity.
Because counting tongue papillae is usually done manually, and a tongue has hundreds of tiny fungiform papillae, mistakes are easy to make. Wang and Sporring developed a new method that automates the counting and delivers precision. Using an algorithm, they designed a tongue-coordinate system that can map papillae on individual tongues using image recognition.
The analysis demonstrated that the Chinese test subjects generally had more of these papillae than the Danish subjects, a result that the researchers believe explains why Chinese people are better at tasting bitter flavors.
However, Bredie emphasizes that larger cohorts need to be examined before any definitive conclusions can be drawn about whether these apparent phenotypical differences between Danes and Chinese hold at the general population level.
More knowledge about differences in taste impressions can be important for food development. “It is relevant for Danish food producers exporting to Asia to know that Asian and Danish consumers probably experience tastes from the same product differently,” Bredie says. “This must be taken into account when developing products.”
Bitter taste and texture
Genetics are only one of several factors that influence how we experience food, Bredie says. Another significant factor has to do with our preferences—including texture. Think, for example, of the difference between munching on crispy potato chips from a newly opened bag, compared to eating softened ones from a bag opened the day before.
Here, many Danes would probably prefer the crispy ones over the soft ones, even if the taste is similar. According to the new studies, there seems to be a difference between the Danish and Chinese test subjects on this point as well.
While the vast majority of Chinese subjects (77%) prefer foods that don’t require much chewing, the opposite holds true for the Danish subjects. Among the Danes, 73% prefer eating foods with a harder consistency that require biting and chewing—rye bread and carrots, for example.
The reason for this difference remains unknown, but the researchers suspect that it stems from differences in food culture and the ways in which we learn to eat. The studies do not point to tongue shape as making any difference.
The studies appear in Food Quality and Preference and Medical Image Computing and Computer Assisted Intervention–MICCAI 2020.
Additional researchers from the University of Copenhagen, the University of Milan; and Arla Innovation Centre. The research received support from Arla Foods amba and the Capital Region of Denmark.
Source: University of Copenhagen