Table 1.

Summary of tastant and solvent concentrations investigated at the initial visit. All concentrations in ppm and percentage are by volume.

Tastant	Taste/oral sensation	Concentrations investigated	Solvent
Sucrose	Sweet	0.25 M, 0.5 M, 1 M	Water
Caffeine	Bitter	4 mM, 8 mM, 20 mM	Water
L-Menthol, (1 R,2 S,5 R stereoisomer)	Cooling sensation	50 ppm, 100 ppm, 250 ppm	Water and ethanol (9.5 × 10−3%, 0.019% and 0.475% respectively)
Capsaicin	Warming sensation	0.1 ppm, 1 ppm, 2.5 ppm	Water and ethanol (9.5 × 10−3%, 0.095% and 0.24% respectively)