The concept of foods being an ‘acquired taste’ should not be dismissed as pretentious nonsense. Scientists from the Karolinska Institutet in Sweden have discovered that a liking for new flavours can be learned with repeated exposure.
Their work, part of the EU-funded OLFLINK project, could make a contribution to addressing the issue of poor nutrition - one of the greatest present day threats to global health.
The researchers are working to unlock the secrets to people’s willingness to embrace unfamiliar foods. The underlying idea is that by building a better understanding of how flavour preferences are formed, it may be possible to influence their development.
They found that repeated exposure, conscious consumption, and introducing unfamiliar items when full rather than hungry are the keys to training people to accept new, healthy foods.
Overcoming the taste obstacle
One of the biggest barriers to changing diets is taste. This has long been a headache for product developers because removing fat, salt, or sugar impacts taste, and novel solutions such as plant-based proteins often fall short of consumer taste expectations.
“All of these foods share the same challenges that are of importance for acceptance, namely that their flavour profile can be considered a variant of a familiar food, and that they tend to be lower in calories. I am trying to understand how these aspects interact on a very basic level, assuming that the learning process would be comparable for all of them,”
Janina Seubert, senior researcher at the Karolinska Institutet, told this publication.
She continued: “We know that for any new flavour, exposure is key, and that post-ingestive feedback on energy intake helps to support the creation of a new preference. A lower energy content is likely making it harder to create a new preference - how can we work around that? Is it more relevant for some people than others, when you are hungry or full, when you are paying attention or not?”
She said that these are some of the questions the researchers are aiming to address in the hope they can support the transition to healthier and more sustainable food options.
The OLFLINK project started in May 2021 and runs through to May 2026. Whilst the majority of the data is still to come, Seubert said the research had already produced some interesting insights.
“We have previously shown that learned associations between the senses, such as vanilla smell and sweet sugar taste, greatly increase liking, but we lacked understanding of how this perceptual mechanism interacts with other modulators of flavour enjoyment, such as hunger,” Seubert said.
Hunger does not improve acceptance
Whilst Seubert and her colleagues thought that these associations would diminish in importance when people were hungry, a study they conducted (currently in preprint) suggested was not the case. It found that hunger does not, for example, increase acceptance of unfamiliar flavours, which under conditions of satiety would be rejected, nor does it specifically enhance pleasantness of familiar flavours.
“Even when hungry, we prefer familiar over unfamiliar combinations when given a choice, but both will be more appealing when hungry than when full,” she said.
Previous exposure a factor
Another surprising finding was that, above all else, the factor that determined whether people found a flavour enjoyable was whether they had been exposed to it before. Flavour learning enhanced the perceived pleasantness of the stimulus material when it was encountered for the second time relative to the first.
“This indicates that liking for novel flavours can be learned very quickly - even in adulthood - with sufficient repeat exposure,” Seubert explained.
More open to new flavours when full
In another line of investigation, the researchers have found that people are more sensitive to variations when they are hungry, indicating that selectivity for familiar foods may increase when food intake is imminent.
“Given that most novel foods can be conceptualised as variants on familiar foods, but with slight variations in flavour, this may indicate that tolerance for new foods may be higher in a sated state,” noted Seubert.
She said the team will explore this in more detail and will produce a paper on this subject in spring 2024.
Summing up the project’s progress so far, Seubert said: “Our findings to date indicate that repeated exposure is key and that, while attentional focus on the task itself is beneficial – conscious consumption as opposed to consumption in front of the television – particular attentional strategies on different elements of the new flavour may not be necessary.
“It could also be a good idea to introduce new items towards the end rather than the beginning of a meal, but we will need to investigate this part further.”
