Abstract
In sensory evaluation of odor, odor thresholds are very important indicators. We examined correlation between odor thresholds and affinity of odorants for phospholipids for the purpose of developing a method to estimate odor thresholds. Phospholipids are main components in biomembranes of olfactory cells. And we developed a new method of estimate affinity between odorants and phospholipids. Namely, the method is that retention times of odorants are measured by the Gas Chromatography with a column packing a support coated with a phospholipid. The phospholipid is phosphatidylcholine or phosphatidyl ethanolamine in this experiment. Generally, the longer a retention time of an odorant is, the higher a degree of affinity for the phospholipid is. Therefore, the retention time is very rather effective parameter to represent a degree of affinity for the phospholipid.
Odor thresholds of 136 odorants in eight homologous series, those are alkanes, alcohols, ketones, aldehydes, esters, acids, aromatic compounds, sulfuric compounds and amines, were measured by the triangle-choise method with odor bags. Moreover, retention times of the odorants, excepting two seties of acids and amines, were measured by the GC-FID (Flame Ionization Detector) method and GC-FPD (Flame Photometric Detector) method. And correlation between odor thresholds and retention times of the odorants were examined in each series.
As a result, it was made clear that the both have very good relationship mutually in six series, excepting one series of sulfuric compounds. From this result, moreover, it was supposed that phospholipid membrane plays an essential role in olfactory recepting process of molecules.
