Thermal Tasters and Supra-Threshold Sensitivity
Last time I updated on the work of our PhD student, Candy, she was putting a poster together for the PFSG Conference. Subsequent to that I am delighted to report that Candy won a Travel Award from Nottingham University and was able to attend Pangborn 2013 in Rio de Janeiro to present the findings of the most recent steps in her research. These steps explored how thermal taster status effects supra-threshold sensitivity.
What makes someone a Thermal Taster?
A thermal taster (TT) is someone who detects a taste sensation when their tongue is either heated or cooled, when no taste stimulus is present! The temperature of the tongue is manipulated using a special thermode device. The tongue is heated between 15 to 40o C and cooled from 35 down to 5o C. The phenomenon was first reported by Cruz and Green in 20001 and in 2004 Green went on to report that Thermal Tasters (TTs) perceived supra-threshold stimuli as more intense than Thermal non Tasters (TnTs)2. Candy's latest piece of work was to investigate these findings further.
So what have we learnt?
Candy has screened 204 subjects for their Thermal Taster Status of whom 105 participated in this supra-threshold study. Subjects rated the intensity of five series of taste and trigeminal sensations namely sweet, salt, bitter, acid and capsaicin (heat) plus the intensity of cool and warm.
Results showed that TTs rated both trigeminal and taste sensations more intensely than TnTs; the effects were more significant for the trigeminal sensations. Thermal tasters also rated temperature significantly higher.
Candy has also measured the relationship between TT and PROP taster status; it seems as if the two work separately to each other so being one doesn't mean you will be the other.
These findings are clearly interesting for anyone looking to optimise the flavour of hot, cold or spicy foods and beverages. They might even go some way to help in understanding our differences in preference for Friday night curry!
The work will be reported in the scientific literature over the next few months but if you require more information before then please get in touch. The subjects Candy used are members of the Sensory Dimensions' consumer panel database. If you are interested in using the TT and TnT groups in your consumer research then we would be delighted to discuss.
Our thanks go to Nottingham University for its support of this project.
1Cruz, A and Green, B.G. (2000). Nature, 403, 889-892
2Green, B.G. and George, P. (2004). Chemical Senses, 29(7), 617-628