- A lexicon describing the sensory perception of carbonated water was
developed. Temporal aspects and differing ingestion conditions were
investigated for Bite and Burn sensation using time-intensity (T-I). Four CO₂
levels (0, 1.7, 2.8, and 4.6 volumes) at 3°C and 10°C were tested. Trained
panelists used a 16-pt category scale for evaluation in the first study. One
swallow (15 ml) and four continuous swallows were evaluated by trained
subjects using T-I in the subsequent studies.
Lexicon included: salty, sour, bitter, cooling, astringency, bubbly,
bubble size, bubble sound, gas expansion feeling, bite, burn, and numbing.
Descriptor ratings, except cooling, increased as CO₂ level increased. Bubble
size and bubble sound were rated higher for 10°C. Cooling, bite, burn, and
numbing were rated higher for 3°C . Descriptors were divided into cooling,
taste (salty, sour, bitter, astringency), trigeminal (bite, burn, and numbing),
and mechanoreception descriptors (bubbly, bubble size, bubble sound, gas
expansion feeling) based on PCA.
Average temporal curves for Bite and Burn demonstrated that Burn
sensation (steep linear rise and long-lived exponential decay slope) was
similar to previously investigated irritants while Bite (steep linear rise and
decay slopes, and relatively short duration) was unlike other irritants.
Sensations were qualitatively and quantitatively different. Intensity and
duration of Bite and Burn were concentration dependent. Cold temperature
enhanced perception. Possible psychological habituation or desensitization
was observed. Most T-I parameters were correlated for both Bite and Burn.
These included CO₂ level dependent and CO₂ level independent
parameters. Considerable subject variability was found.
Increased exposure to CO₂ solution and increased cooling with
ingestion of four continuous swallows was compared to one swallow. T-I
curves for Bite (four swallows) were of higher intensity, longer duration, and
developed maximum intensity plateaus. Those for Burn exhibited higher
maximum intensities. At four swallows, T-I parameter correlations were
strengthened, subject variability reduced and replication reproducibility
improved by ease of rating afforded subjects by higher intensity sensations.
Increased oral CO₂ perception with higher CO₂ levels and enhancement by
cold temperature was reconfirmed. Beginnings of maximum intensity,
Duration, and reaction time perceptual terminal thresholds were seen for the
highest 3°C, CO₂ level. High CO₂ concentration, cold temperature, and
exposure time induced these effects.