Sensitivity of three loci on the tongue and soft palate to four basic tastes in smokers and non-smokers.

The filter paper disk method was used to determine the map of the 4 tastes (sweet, salty, sour and bitter) on the tongue and soft palate in 69 healthy individuals. The equipment used for testing included filter paper disks 8 mm in diameter and taste solutions, which were sequentially diluted (in 13 stages from 80% sucrose, 12 stages from 20% NaCl, 12 stages from 8% tartaric acid and 14 stages from 4% quinine hydrochloride). The threshold at which each taste was recognized in three locations (center of the tongue tip, foliate papillae on the left side and center of the soft palate) was determined by testing increasing concentrations of each solution. We found no difference by sex for sweet taste but women were more sensitive to sour taste on the tongue tip and to salty and bitter tastes on the soft palate. No difference in taste threshold was noted at the different locations for sweet, salty or bitter tastes, but both sexes were less sensitive to sour taste on the soft palate than on the tongue tip, and in men the soft palate was even less sensitive to sour taste than the tongue root. Smoking was associated with increased (worse) taste thresholds for all four tastes, for both men and women.