An Investigation of Taste Intensity, Palatability, Effervescence, and Sip Volumes of Carbonated Liquid Stimuli for Use in Videofluoroscopic Studies.

Purpose Existing studies examining the effect of carbonated fluids on swallow physiology under videofluoroscopy (videofluoroscopic swallowing studies [VFSSs]) have significant variability across the fluids tested and limited consideration of the stability of the carbonation or fluid palatability. This study compared the effervescence behavior, carbonation intensity (sour, bite, bubble), palatability, and sip volumes of carbonated liquids as used in VFSSs and control samples. Method Forty-two healthy women (20 supertasters, 22 nontasters; 20-61 years old) took sips of 4 different liquids (water, carbonated water, barium sulfate with sodium bicarbonate granules, and barium sulfate with carbonated water) across 2 time conditions (on preparation and 5 min postpreparation). The 8 conditions were presented in 100-ml amounts, in randomized order. At presentation of each fluid, participants immediately rated effervescence via visual inspection. Then after sips of each fluid, participants rated perceived intensity of sour, "bubbles" and "bite," and palatability. Sip size was derived from residual volumes. Participant perceptions of fluids were also collected. Results The effervescence of barium sulfate with sodium bicarbonate granules, as used in the majority of published studies, was most impacted by time (p < .05), rated poorly for palatability, and had the largest impact on sip size (p < .05). Participant comments regarding the VFSS fluids were grouped in 4 themes: (a) adverse/other reactions, (b) awareness of sensory properties, (c) physiological reactions, and (d) swallow changes. Conclusions The significant differences between liquids regarding effervescence behavior, impact of preparation time, palatability, impact on naturalistic sipping, and patient perceptions warrant consideration when testing carbonated fluids during videofluoroscopy.