Drinking hot chocolate from an orange mug makes it taste sweeter, tasting a liquid whilst touching velvet makes the texture creamier and drinking champagne whilst listening to classical music can increase liking.
But are food companies who make use of such techniques essentially manipulating people?
Not according to Barry Smith, founder of the Centre for the Study of the Senses. Speaking this week at Food Matters Live in London, Smith believes there is a difference between leading and misleading consumers.
“We are leading people to what’s already there,” he said. Dark chocolate has both bitter and sweet notes, but tasting it under certain circumstances will accentuate certain flavours. If you eat it while listening to high, tinkling music this auditory cue will bring out the sweet flavour, and vice versa for low-pitched music.
Use it positively
Sensory adaptation could also be used to have a positive impact on public health. Airplane food is notoriously bland, despite the best efforts of airlines to make it taste better. While a myriad of factors are at play, from high altitude to low pressure and dry atmosphere, another element is white noise.
Decibel increases suppress the brain’s ability to perceive salt, sweet and sour by up to 10%. Many passengers over salt their food to compensate, but some airlines have taken a direct approach to remedying this – Lufthansa gives its business class passengers noise-cancelling headphones, said Smith.
“There are lots of ways to change behaviour. [The questions is] how to get a level of nudging or adjusting but in a way that people don’t feel they’re being manipulated.”
The first consumer taste tests for fat-free yoghurt generated negative feedback because the yoghurt was too runny. The products developers responded by adding emulsifiers but consumers found the yoghurt had a gluey consistency. The answer was to add certain odours that are associated with creaminess or to make the yoghurt heavier as weight is associated with higher fat content.
“These kind of nudge techniques can push people to make healthier choices,” said Smith, adding that it was important to not give consumers the impression they are being manipulated.
Lead researcher at the Smell and Taste Clinic in Dresden, professor Thomas Hummel, said there was a delicate balance to strike. “People are very different in their responses, even if you are exposed to a smell you like for a long time you can get annoyed by it. This is a problem for marketing.”
Smith agreed that multisensory experiences are most effective when they occur imperceptibly: “The smells that do work are the ones that are so low you don’t notice. You walk [into a hotel scented with vanilla] and feel relaxed. It’s under the radar.”
According to Agnes Giboreau, director of research at the Institut Paul Bocuse and specialist in perception and eating behaviours, presenting a variety of colour on a plate serves to increase the visual pleasure and could thus increase consumption of healthy foods such as vegetables. She suggested this technique could be used to get the elderly or hospital patients to eat more.
Portion size and choice architecture
Altering the choice architecture and presenting food options in such a way so as to encourage people to choose smaller portions could also promote healthier eating.
But as many food companies may have experienced, when portions are made smaller they do not sell as well – consumers feel they are being cheated. What can be done in this case?
Giboreau said that the perception of quality is adjusted in consumers’ minds depending on the overall supply, so in order to encourage consumers to choose smaller portions there must be fewer large portions on offer.