Understanding heat and chilling could boost flavour perception

"Understanding the effect of exposure on flavour perception, particularly to new combinations of stimuli has particular relevance to new product launches and their acceptance by the consumer," wrote the researchers, led by Joanne Hort, in the journal Food Quality and Preference.

How consumers sense food is crucial knowledge for a food industry constantly organising the building blocks of new food formulations.

The new research, supported by Switzerland-based Firmenich, looked at how flavour perception and acceptance was affected by chemesthesis, the chemical stimulation of free nerve endings which results in sensations such as cooling (like from menthol) or hot (like from pepper).

Trained panellists evaluated flavour, aroma, colour and cooling intensity of two drinks containing an odourless, tasteless cooling compound (WS-3).

One drink was coloured green and given a melon aroma and the other coloured purple and given a pineapple aroma.

The researchers report that colour was in no way related to how the panellists perceived flavour or cooling intensity.

On the other hand, the aromas were found to enhance the cooling intensity, and the presence of the coolant found to enhance the flavour.

"[This indicated] some perceptual interaction between the olfactory and chemesthetic stimuli," they said.

"This study provides further evidence that aroma-chemesthetic interactions impact on flavour perception, and that unlike capsaicin, cooling appears to enhance fruit flavour intensity at the levels used in this study," they added.

The researchers said it was interesting that chemically induced cooling enhance flavour perception, while chemically induced hotness had been reported to reduce flavour perception.

"One reason for this phenomenon could be that cooling is perceived as a positive sensation," they said.

"If perceived as positive then perhaps this is why cooling enhances flavour to encourage consumption."

The lack of an interaction between colour and flavour perception or cooling sensation observed in this study may indicate that colour has a more marked impact on pre-consumption where there may be an indication of flavour identity and expectation.

"It will be interesting to know if these associations are fixed or deteriorate without continued exposure, although [previous work by other researchers] on taste-odour interactions would indicate that they remain intact," concluded the researchers.

"Furthermore, understanding how the brain learns to associate sensation from different stimuli may help to develop strategies to encourage the population to learn to like reduced salt, sugar or fat products."

Taste is a key driver in the €3.2 trillion global food industry and a greater understanding of the physiology of consumers, could lead to strong market advantages.

Source: Food Quality and Preference Published on-line ahead of print, doi: 10.1016/j.foodqual.2007.02.033 "Colour-coolant-aroma interactions and the impact of congruency and exposure on flavour perception" Authors: C.E.F. Petit, T.A. Hollowood, F. Wulfert, J. Hort