Structure-Odor Relationships of (E)-3-Alkenoic Acids, (E)-3-Alken-1-ols, and (E)-3-Alkenals

摘要

(E)-3-Unsaturated volatile acids, alcohols, and aldehydes are commonly found as odorants or pheromones in foods and other natural sources, playing a vital role in not only the attractiveness of foods but also chemo-communication in the animal kingdom. However, a systematic elucidation of their aroma properties, especially for humans, has not been carried out until today. To close this gap, the odor thresholds in air and odor qualities of homologous series of (E)-3-alkenoic acids, (E)-3-alken-1-ols, and (E)-3-alkenals were determined by gas chromatographyolfactometry. In the series of (E)-3-alkenoic acids the odor quality changed successively from sweaty via plastic-like to sweaty and waxy. On the other hand, the odor qualities in the series of (E)-3-alken-1-ols and (E)-3-alkenals changed from grassy, green to an overall citrus-like, fresh, soapy, and coriander-like odor with increasing chain length. With regard to their odor potencies, the lowest thresholds in air were found for (E)-3-heptenoic acid, (E)-3-hexenoic acid, and (E)-3-hexenal.