Analysis of Volatile Phenolic Compounds Responsible for 4-vinylguaiacol-like Odor Characteristics of Sake

Sake samples having characteristics of 4-vinylguaiacol (4-VG)-like odor were analyzed by GC-MS and organoleptic methods. The quantified levels of 4-VG, 4-vinylphenol, 4-ethylguaiacol, and 4-ethylphenol of 15 sake samples, including 7 samples presenting 4-VG-like odor characteristics by multiple assessors, did not show a clear relation with the perception rate of 4-VG-like odor characteristics. Hence, we screened for other compound(s) responsible for the 4-VG-like odor characteristics, and found that odorous sake samples contain 2-methoxy phenol (guaiacol), 2,6-dimethoxyphenol (syringol), and 3-methyphenol at higher levels than the odor-less sample. The quantified level of guaiacol well matched the perception rate of 4-VG-like odor characteristics. The recognition threshold value of guaiacol in the sake and of 4-VG in the model sake solution was estimated as 14.6 µg/L and 141 µg/L, respectively. The concentration of guaiacol in the most odorous sake samples was higher than the estimated recognition threshold.