The research, conducted by the faculty of human nutrition and consumer sciences at the Warsaw University of Life Science, is some of the most detailed to date on how our perception of ‘hotness’ is altered by different food matrices.
Unlike flavour perception in the nose and mouth (smell and taste), heat perception from food is moderated by the chemesthetic stimulation system. Chemesthetic sensations are perceived via temperature and pain receptors; develop at a slower rate than smells and tastes, and are far more persistent, research leader Eliza Kostyra told Foodmanufacture.co.uk.
The sensation of ‘hotness’ also varied qualitatively over time, and depended partly on the food matrix, said Kostyra, who has been feeding trained panellists chicken, tomato and mushroom soups and sauces containing different amounts of chilli powder.
Interestingly, chicken soups and sauces were perceived as considerably hotter than tomato soups and sauces and mushroom soups and sauces containing equal quantities of chilli, said Kostyra: “With equal amounts of chilli added, the flavour of the chicken soup and sauce was perceived as considerably hotter, with a longer lasting ‘after-burn’, than the tomato and mushroom soups and sauces.”
Adding chilli to tomato dishes also seemed to suppress the tomato flavour more than adding the same amount of chilli to a chicken dish suppressed its ‘chickeny’ flavour, she said. “The degree of suppression varied depending on the product. The effect was much stronger in the tomato samples than in the two others [chicken, mushroom].”
The flavour-suppressing effect of chilli also appeared to be stronger in soups than in sauces: “It was much more evident in the soups and depended on the kind of flavour in the sauces.” The perceived chilli hotness was also more intense in the soups than the sauces: “It may be that the starch content and resulting higher viscosity of the sauces impeded the contact of the chilli with the receptors.”
How chilli powder impacts salt perception
Although all the sauces and soups in the trial contained the same level (0.6%) of salt, the panellists’ ability to detect ‘saltiness’ was also impacted by the chilli powder, she added. For example, panellists perceived the samples containing no chilli to be more salty than those containing chilli, even though they all contained exactly the same amount of salt. But there were also big differences between samples with no chilli, she said: “Interestingly, the perceived saltiness in the control samples without added chilli was very different: it was almost 2.5 times higher in chicken and mushroom than in tomato soup.”
She added: “A low amount of chilli (0.03%) enhanced the slightly salty taste in tomato soup; but suppressed it strongly in chicken soup and even more in mushroom soup.”
In the course of the study, which has just been published in the journal Food Quality and Preference (volume 21, issue 2, March 2010) the researchers served chicken, tomato and mushroom soups and sauces to a panel of six trained sensory experts.