Variation in orosensation and liking of sampled foods with thermal tasting phenotype

Abstract

Background: Flavour is a key driver of liking, purchase behaviour and consumption of food and beverages. Determining how individuals differ in their perception of flavour is important to fully understanding dietary choices and habitual diet-related health outcomes. Thermal tasting-the capacity to experience a phantom taste when small areas of the tongue are rapidly heated or cooled-associates with greater orosensory acuity for tastants in aqueous solutions. This study sought to extend this finding and establish whether thermal-taster status also associates with the perceived intensities of oral sensations elicited by sampled food. Twenty-five thermal tasters (TTs) and 19 thermal non-tasters (TnTs) scored liking (generalized degree of liking scale) and the intensity (generalized visual analogue scale) of the dominant orosensations elicited by 20 food and beverage items in duplicate using a randomized complete block design. Results: Multiple analysis of variance (MANOVA) showed that overall, TTs rated the intensity of orosensory food groups higher than did TnTs, although this was significant only for foods that were predominantly bitter-eliciting (ANOVA). Overall liking scores approached significance (MANOVA) but differed between TTs and TnTs only for the grainy orosensory food grouping (ANOVA).

Variation in thermally induced taste response across thermal tasters

“…Twenty eight percent of participants phenotyped in this study were TTs, which is within the 20% [1] – 50% [8] range previously reported. Fifty one percent of participants were classified as TnTs, within the range previously identified 29% [30] to 77% [16] , but higher than the typical 35–40% reported in most studies [1] , [2] , [19] , [22] , [23] . Twenty one percent of participants were Uncat , lower than previous findings which range from 23% [22] – 42% [30] , and considerably lower than the 33–42% typically reported [1] , [2] , [3] , [30] .…”

“…In the past, some researchers have classified TTs as those reporting only prototypical taste qualities [3] , [8] , whilst others, including the current study, have permitted ‘other’ attributes (minty, metallic, spicy) [16] , [20] , [21] , [22] , [30] . Although controversial, it is important to understand how these sensations relate to the thermal taste phenomenon, and to characterise the complete range of sensation reported in addition to the perceived temperature across TTs.…”

“…Sweet was perceived significantly more frequently during the warming trial, and bitter and sour during the cooling trial. Early literature on TTs failed to report which taste qualities were perceived, and more recently some researchers have grouped tastes perceived across both trials together [20] , [22] . When tastes have been identified across separate trials, sweet, metallic and bitter are frequently perceived when warming the tongue, and sour, bitter, metallic and salt when cooling [8] , [16] , [21] , [30] , as found in the current study.…”

“…TTs are frequently observed to rate the intensity of gustatory and some trigeminal stimuli more intensely than TnTs [1] , [13] , [15] , [30] , as well as some attributes in complex foods and beverages [19] , [20] , [22] , [23] which may be associated with food preference [22] . It is unknown whether thermal sensations are also elicited when consuming food and beverage at warm and/or cool temperatures.…”

“…TTs perceptual advantage has been supported in a recent study showing increased cortical activation in multiple brain regions in response to gustatory-trigeminal stimuli in TTs compared to TnTs [16] . Some evidence suggests thermal taster status may also influence food preference [22] . However, the heightened oral responsiveness that TTs exhibit to attributes in alcohol and some food products does not always translate to a difference in overall preference [19] , [20] , [22] , [23] .…”