RESUMO
BACKGROUND AND OBJECTIVES: Using n-aliphatic alcohols whose physical properties change gradually as their length increases, we investigated the changes of olfactory threshold and trigeminal pungency threshold with the increase of carbon chain length. MATERIALS AND METHOD: Olfactory and trigeminal pungency thresholds were measured in ethanol (C2), 1-butanol (C4), 1-hexanol (C6) and 1-octanol (C8) in 40 normal adults using a two-alternative forced-choice modified by the ascending method of limit (CCCRC) test. Plastic bottles with 30 ml of four n-aliphatic alcohols were diluted threefold successively by mineral oil. Plastic bottles containing only mineral oil were used as controls. RESULTS: The olfactory and trigeminal pungency thresholds decreased and the ratio of olfactory threshold/trigeminal pungency threshold increased with the length of carbon chain in n-aliphatic alcohols. The correlation coefficients among olfactory thresholds in each alcohol were higher than those among trigeminal pungency thresholds. CONCLUSION: Alcohol with long carbon chains showed low olfactory and trigeminal pungency thresholds, indicating that high lipid solubility is an important factor in olfaction and trigeminal chemosensitivity.