著者

大河内 正一 石原 義正 稲葉 慎 上平 恒

出版者

公益社団法人 日本農芸化学会

雑誌

日本農芸化学会誌 (ISSN:00021407)

巻号頁・発行日

vol.68, no.8, pp.1215-1218, 1994-08-01 (Released:2008-02-14)

参考文献数

13

被引用文献数

4 5

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The line width (full width at half maximum intenslty) of 170 nuclear magnetic resonance signals and the spin-lattice relaxation time, T1, of aged commerclal distilled spirits and aqueous ethanol solutions were measured at 298K. The values of T1 for the 17O nucleus of water (which reflects the mobility of the water molecule) in both kinds of preparations did not change over the pH range of 2 to 13, but the line width broadened at pH from 5 to 9, as did that of pure water. That the broadenlng, whlch reached about 1OO Hz at pH7.0, depended on pH seemed to be due to changes in the exchange rates of protons. The T1s of the aged commercial splrits and the ethanol solutions of the same concentration were almost the same. Therefore, when the line width of the 170-NMR signal is to be used as an index of the aging of spirits, it must be taken into account that the width depends on the pH of the materials.