In a recent report published in Food Quality and Preference, researchers at the University of Nottingham studied the color, coolant and aroma interactions and their impact on flavor perception. One of the main goals of the study was to explore how flavor perception and acceptance were affected by chemesthesis, the chemical stimulation of free nerve endings which results in sensations such as cooling (menthol) or hot (peppers). In addition, according to corresponding author Joanne Hort, the study was testing “our theory that color affects expected intensity but has less of an effect when you actually consumer a sample.” Thirdly, the researchers tested the assumption that congruency between stimuli can be learned through experience.
Trained panelists rated flavor and cooling intensity using labeled magnitude scales for a range of congruent (green-coolant-melon) and incongruent (purple-coolant-pineapple) combinations. The panel was then split into two groups and exposed (five weeks) to either the congruent or incongruent beverage mixture, after which the flavor and cooling intensities of the incongruent mixture were reassessed.
Not surprisingly, the researchers found that the level of coolant affected the cooling perception and aroma concentration affected flavor perception. However, the authors also found that the presence of the aroma enhanced the coolant intensity and that the presence of the coolant also enhanced the melon intensity. These findings indicate that there is a perceptual interaction between the olfactory and chemesthetic stimuli.
Hort explains that “an unexpected finding was that color has less influence than we had expected [on flavor perception].” In fact, color intensity had no impact on perceived flavor or cooling intensity. This reinforces the idea that color has much more of an impact pre-consumption, where they may be an indication of flavor identity and expectation.
Another interesting finding was that although panelists believed purple-coolant-pineapple to be completely unassociated with each other, after repeated exposure the aroma concentration appeared to enhance cooling and that coolant concentration enhanced perceived pineapple intensity. It appears that this association between incongruent stimuli can be learned through experience.
Taking it to the Lab
Understanding the effect of exposure on flavor perception, particularly to new combinations of stimuli is extremely relevant to the job of a flavorist, especially when it comes to new product launches and their acceptance by the consumer. According to Hort, one tangible conclusion flavorists can take away is that “clearly cooling compounds can be used to enhance some congruent aromas and vice versa.”
Gary Reineccius (University of Minnesota), who reviewed the study for P&Fnow, believes that the results of this study are very important for flavorists, stating that, “It reinforces the idea that flavorists must look at the total system—not just the aroma. To recreate a flavor perception ALL of the stimuli must be presented—taste, aroma, color, texture, mouthfeel, etc.”
In addition, this study is a step towards understanding how the brain learns to associate sensation from different stimuli, which may help to develop strategies to encourage the population to learn to like reduced- salt, sugar or fat food products.
Petit, C.E.F. et al., Colour-coolant-aroma interactions and the impact of congruency and exposure on flavour perception, Food Quality and Preference (2007)