Construction of a Screening Test for Gustatory Function in Four Basic Tastes

Abstract

The purpose of this study was to determine the effectiveness of a screening test for gustatory function in four basic tastes using a whole-mouth test with one concentration of a taste solution together with the Visual Analogue Scale (VAS) score.
 In experiment 1, 84 healthy subjects were recruited to determine the concentrations used for whole-mouth gustatory tests in this study.
 The subjective intensity of taste was scored by the VAS, to be evaluated as the sensitivity of gestation (hereinafter known as gustatory VAS score).
 In experiment 2, four subjects were randomly pick up from the subjects of experiment 1. The diurnal variation and day-to-day variation of the gustatory threshold value of four basic tastes were investigated.
 In experiment 3, the results from a screening test for gustatory function in four basic tastes using each of the concentration obtained in experiment 1 were investigated.
 The results obtained were as follows:
1. The lowest concentration that could be identified by all subjects was 0.075 M for sucrose, 0.2 M for sodium chloride, 2.0×10^-3 M for citric acid, and 7.5×10^-5 M for quinine hydrochloride.
2. The following observations were made using the screening test for gustatory function developed in this study, Seven of the 25 subjects (28%) were diagnosed as taste decrease. Within the limitation of research design, these results demonstrate that gustatory function in four basic tastes could be assessed using a whole-mouth test with one specific concentration of a taste solution combined with the VAS score. Therefore, this method could be used as a screening test for gustatory function in four basic tastes.