For most people, biting into a lemon would leave them agonized and desperate for that sour taste, but a new study by Penn State researchers found that about one in eight adults enjoy intensely sour sensations. The cross-cultural study, recently published in the journal Food quality and preferencedemonstrated that there is a subgroup of “sour likers” who enjoy exceptionally sour foods.
“This is the first time it has been conclusively shown that there is a segment of adults that like strongly sour things,” said John Hayes, professor of nutritional sciences, director of the Sensory Evaluation Center at Penn State and author of the study.
Previous studies have shown that some children, about one in three, like intensely sour things, Hayes explained, but this had not been tested directly in adults. His recent study, conducted in collaboration with researchers in Italy, was the first to show that for a significant number of people, the pleasure of sourness continues well into adulthood.
“Think of candies like Warheads and Sour Patch Kids,” Hayes said. “The market tells us there must be people who will enjoy it into adulthood, but now we have an estimate of the number.”
The international research team wanted to test the widely held belief that adults are generally averse to sourness, which they predicted would result in a decrease in taste as sourness increases. They tested the taste patterns of sourness in two different countries among two different groups of individuals belonging to different food cultures: Italy and the United States.
The team measured the responses of 143 American adults to different levels of citric acid in water. They also measured the responses of 350 Italian adults to pear juice with varying amounts of citric acid added. They selected participants of similar age, gender, and ethnicity (majority white) from a metropolitan area in Tuscany, Italy, and from the municipality of State College.
Participants were asked to rate the intensity and flavor of a series of samples with different sourness levels. For both cohorts, the researchers found evidence of three different response patterns: a strongly negative group where taste decreased with increasing sourness, an intermediate group that showed a more muted decrease in taste with more sourness, and a strongly positive group where taste increased with increasing sourness , and a strongly positive group where flavor increased with increasing sourness. more sourness.
“Most people didn't like sourness, so if you averaged the whole group, you would conclude that more sour equals bad,” says Hayes. “But when you dig deeper, you discover enormous differences between people.”
By measuring the degree of liking, the researchers were also able to test the hypothesis that 'sour likers' might be less sensitive to sour foods; the theory that higher concentrations of sourness for 'sour likers' registered the same as lower concentrations of sourness in sour foods. someone else.
“You can imagine a case where they're just less responsive to acidity in general,” Hayes said. “But that's not what we find. We find that people who like a very sour taste actually experience it as sour as other people. They just enjoy it more.”
Strikingly, the researchers noted that both the Italian and American cohorts showed similar proportions of response patterns to sourness, with about 63% to 70% in the strongly negative group and roughly 11% to 12% in the strongly positive group. are stable across cultures.
“Italian food culture and American food culture are so vastly different,” said Sara Spinelli, a researcher at the University of Florence in Italy and first author of the paper. “And yet we end up with almost identical percentages, which indicates that this is not an effect of previous exposure. It's probably something completely different about those people. We don't know what that is, but it tells us it's not just the food you grew up with.”
The researchers noted that the data support the existence of previously undiscovered flavor profiles that respond positively to sour stimuli. Given that sourness is classically considered a negative sensory attribute, the researchers were surprised to find that about 1 in 8 participants from both countries showed an increase in taste as sourness increased.
“This study highlights the importance of looking at individual differences and potential consumer segments, rather than simply averaging the responses of all individuals within a group,” Spinelli said. “Because when we average the responses, all we see is an aversion to sourness, we lose this subset of people who really like it.”
Hayes explained that this type of segmentation could be used to develop customized products that take into account the specific flavor profile of the 'sour liker'.
“This could ultimately serve to promote the consumption of healthier foods and drinks that are less sweet but still acceptable to consumers,” he said.
