Acidic sensory study reveals subset of adult 'sour likers'

While intense sour flavours may leave the majority of adults puckering with distaste, a study by Penn State researchers revealed that roughly one in eight adults actually like intensely sour sensations. The cross-cultural study, recently published in the journal Food Quality and Preference, demonstrated there is a subset of ‘sour likers’ who enjoy exceptionally sour foods.

“This is the first time it’s been convincingly shown that there is a segment of adults who like strongly sour things,” said John Hayes, professor of food science, director of the Sensory Evaluation Centre at Penn State and author on the study.

Previous studies have shown that some children, roughly one in three, enjoy intensely sour things, Hayes explained, but this had not been tested directly in adults. His recent study, conducted in partnership with researchers in Italy, was the first to show that for a sizeable number of people, the enjoyment of sourness lasts well into adulthood.

The international research team set out to test the widespread belief that adults are generally averse to sourness, which they predicted would result in a drop in liking as sourness increases. They tested the liking patterns of sourness in two different countries across two different groups of individuals belonging to different food cultures — Italy and the United States.

Participants were asked to rate the intensity and liking of a range of samples with varying sourness levels. For both cohorts, the researchers found evidence of three distinct patterns of response: a strong negative group where liking dropped with increased sourness, an intermediate group who showed a more muted drop in liking with more sourness and a strong positive group where liking increased with more sourness.

“Most people didn’t like sourness, so if you just average across the entire group, then you’d conclude that more sour equals bad,” Hayes said. “But if you dig deeper, you find huge differences across people.”

By gauging levels of liking, the researchers were also able to test the hypothesis that sour likers might just 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 someone else.

“You could imagine a case where they’re just less responsive to sourness in general,” Hayes said. “But that’s not what we find. We find the people that like really sour flavour actually experience it just as sour as other people. They simply enjoy it more.”

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 strong negative group and roughly 11 to 12% in the strong positive group, suggesting these proportions may be stable across cultures.

“Italian food culture and American food culture are so wildly different,” said Sara Spinelli, a researcher from the University of Florence in Italy and first author on the paper. “And yet we end up with almost identical percentages, which suggests to us this is not an effect of prior exposure. It’s probably something innately different about those people. We don't know what that is, but it tells us that it’s not just the foods you grew up with.”

The study highlights the importance of looking at individual differences and potential consumer segments that like sour taste, rather than just averaging responses.

Hayes explained that this type of segmentation could be used to develop tailored products that account for the specific sour liker taste profile.

“This could ultimately serve to promote the consumption of healthier foods and beverages that are lower in sweetness but still acceptable to consumers,” he said.

To read more about the sour research findings, click here. 

Image credit: iStock.com/FluxFactory