[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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"Spicy/4VG" character is perceived in 5-10% of sake submitted to Sake Contests. However, the aroma compounds responsible for the character are not known except for 4-vinylguaiacol (4VG). We investigated the aroma compounds responsible for the "spicy/4VG" character in sake submitted to Sake Contests in 2013 and 2014. Comprehensive volatile compound analysis revealed that sake with a "spicy/4VG" character contained higher levels of guaiacol, 4VG, lactones, and ethyl esters compared with controls, sake without the character. Among those compounds, guaiacol and 4VG were detected as having "medicine/smoke" and "curry/spicy" odors reminiscent of a "spicy/4VG" character by GC-olfactometry. We then analyzed volatile phenol compounds using SBSE-GC-MS. The concentration of guaiacol tended to increase as the number of panelists indicating a "spicy/4VG" character, and it exceeded its detection threshold (22 μg/L) in several sake samples. Although the concentration of 4VG was affected by the degradation of ferulic acid during thermal desorption process, its concentration was estimated to exceed its detection threshold (52 μg/L) in at least 70% of sake with a "spicy/4VG" character. 4-Ethylguaiacol (4EG) was detected only in a few samples, but one sample with "spicy/4VG" character contained a relatively high level of 4EG. These results indicated that not only 4VG but guaiacol and 4EG contributed to the "spicy/4VG" character of sake.

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