Abstract:
Orosensory perception strongly influences liking and consumption of foods and
beverages. This thesis examines the influence of biological sources of individual
variation on the perception of prototypical orosensory stimuli, food liking, self-reported
alcohol liking and consumption, and indices of health. Two orosensory indices were
examined: propylthiouracil (PROP) responsiveness, a genetically-mediated index of
individual variation associated with enhanced responsiveness to orosensory stimuli
often expressed as PROP taster status (PTS); and thermal taster status (TTS), a recently
reported index of orosensory responsiveness. Taster status in PTS and/or TTS confers
greater responsiveness to most orosensory stimuli. Gender, age, ethnicity, and
fungiform papillae (FP) density were not associated with orosensory responsiveness to
tastants, an astringent, and a flavour. Unlike PROP responsiveness, FP density was not
associated with TTS. Both PROP responsiveness and TTS were associated with
increased responsiveness to orosensory stimuli, including temperature and astringency.
For PROP, this association did not hold when stimuli were presented at cold or warm
temperatures, which are ecologically valid since most foods and beverages are not
consumed at ambient temperature. Thermal tasters (TTs), who perceive 'phantom' taste
sensations with lingual thermal stimulation, were more responsive to stimuli at both
temperatures than thermal non-tasters (TnTs). While PTS, TIS, and gender affected
self-reported liking and consumption of some alcoholic beverages, gender associated
with the greatest number of beverage types and consumption parameters, with males
generally liking and consuming alcoholic beverages more than females. Age and gender
were the best predictors of alcoholic beverageAiking and consumption. As expected, ..
liking of bitter and fatty foods and cream was inversely related to PROP responsiveness.
TTS did not associate with body mass index or waist circumference, and contrary to
previous studies, neither did PROP responsiveness. Taken together, TnTs' greater liking
of cooked fruits and vegetables and high alcohol, and astringent alcoholic beverages
than TTs suggests differences between TTS groups may be driven by perceived
temperature and texture. Neither an interaction between PTS and TTS nor a TTS effect
on PROP responsiveness was observed, suggesting these two indices of individual
variation exert their influences on orosensory perception independently.
