Vanillin modifies affective responses to but not burning sensations from ethanol in mixtures.

Vanillin may modulate perception of noxious oral stimuli via TRP receptor interactions; separately, vanillin has also been shown to have top-down influences on flavor perception. Here, we ask whether added vanillin decreases the perceived burn of ethanol either via peripheral or cognitive mechanisms. Participants rated the burn of ethanol with 0, 16, and 160 ppm vanillin. In studies 1 (n = 102) and 2 (n = 82), participants wore nose clips and rated the burn of 8% and 16% ethanol (study 1) or 32% and 48% ethanol (study 2). In study 3 (n = 65), participants were able to breathe freely and rated liking and perceptual qualities of 8% and 32% ethanol at each vanillin level. Vanillin showed no significant effect on ratings of burn or smoothness, but did increase perceived sweetness (p < .001) and liking (p = .004) in study 3. These data suggest vanillin does not modulate ethanol burn via TRP receptor mediated interactions, but may shift hedonic responses to ethanol via top-down processes.