title: The relationship between phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) taster status and taste thresholds for sucrose and quinine.
abstract: OBJECTIVE
  The aim of this study was to investigate the relationship of taster status with taste detection and recognition thresholds for sucrose and quinine.
  
  
  METHODS
  Sixty-nine subjects (35 men and 34 women; mean age, 23.9+/-1.2 years) were included. Stimulus fluids were prepared, one each for phenylthiocarbamide (PTC), 6-n-propylthiouracil (PROP), sucrose and quinine HCl. In each series, successive solutions, which comprised a total of 15 grades, differed by 0.25log units of the molar concentration. Two concentrations of NaCl (0.32 and 1.0 M) were prepared. The subjects were classified as nontasters and tasters using their PTC and PROP perceptions. Tasters were classified as medium-tasters and supertasters by the ratio of perceived bitterness of above-threshold PROP relative to the perceived saltiness of NaCl (PROP ratio). Taste detection and recognition thresholds for sucrose and quinine were determined by standard two-alternative forced choice trials. A Student's t-test, a Pearson's correlation analysis and linear contrasts in a one-way analysis of variance (ANOVA) were used.
  
  
  RESULTS
  The percentages of nontaster, medium-taster and supertaster were 13, 70 and 17%, respectively. There were no significant gender differences in the taste detection and recognition thresholds for sucrose and quinine. The threshold for PTC and PROP showed significant correlations with taste threshold for quinine. Linear contrast in one-way ANOVA showed that the greater the value of PROP ratio, the more sensitive to sweet and bitter tastes (p<0.001).
  
  
  CONCLUSIONS
  The PTC and PROP taster status is closely related with taste detection and recognition thresholds for sucrose and quinine.
authors.affiliation: Department of Oral Medicine and Oral Diagnosis, School of Dentistry & Dental Research Institute, Seoul National University, Yunkeun-Dong 28, Chongro-Ku, Seoul 110-749, Korea.
authors.forename: Won-Ic
authors.initials: WI
authors.lastname: Chang
authors.forename: Jin-Woo
authors.initials: JW
authors.lastname: Chung
authors.forename: Young-Ku
authors.initials: YK
authors.lastname: Kim
authors.forename: Sung-Chang
authors.initials: SC
authors.lastname: Chung
authors.forename: Hong-Seop
authors.initials: HS
authors.lastname: Kho
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D010670:Phenylthiourea / Q000008:administration & dosage*; D011441:Propylthiouracil / Q000008:administration & dosage*; D011601:Psychophysics; D011803:Quinine / Q000008:administration & dosage*; D012965:Sodium Chloride / Q000008:administration & dosage; D013395:Sucrose / Q000008:administration & dosage*; D013649:Taste; D013652:Taste Threshold
chemical_list: D012965:Sodium Chloride; D013395:Sucrose; D010670:Phenylthiourea; D011441:Propylthiouracil; D011803:Quinine