Oral astringency: effects of repeated exposure and interactions with sweeteners

The perceived dryness and bitterness associated with the astringentstimulus tannic acid were examined in a series of experiments.The method of magnitude estimation was used in conjunction witha sip and spit procedure to measure changes in these two oralsensations during repeated exposures to the test stimulus. Salivaryvolume was also measured. The results indicated (i) that mouthdryness increased significantly over time, whereas bitternessincreased only slightly over time, and (ii) the addition ofsweeteners to solutions of tannic acid reduced both perceiveddryness and bitterness. It was concluded that the attenuationof dryness by sweeteners was probably related to increases insalivary volume produced by the sweeteners, although the lubricatingcharacteristics of the viscous sucrose solutions may also haveplayed a role.