Analysis of the Components of Hard Resin in Hops (Humulus lupulus L.) and Structural Elucidation of Their Transformation Products Formed during the Brewing Process
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- 作者：Yoshimasa Taniguchi ; Harumi Taniguchi ; Makiko Yamada ; Yasuko Matsukura ; Hideki Koizumi ; Kazuo Furihata ; Kazutoshi Shindo
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2014
- 出版时间：November 26, 2014
- 年：2014
- 卷：62
- 期：47
- 页码：11602-11612
- 全文大小：439K
- ISSN：1520-5118
文摘
The resins from hops (Humulus lupulus L.), which add the bitter taste to beer, are classified into two main sub-fractions, namely, soft and hard resins. 伪- and 尾-Acids in soft resin and their transformation during the wort boiling process are well-studied; however, other constituents in resins, especially hard resin, have been unidentified. In this study, we identified humulinones and hulupones as soft-resin components, in addition to 4鈥?hydroxyallohumulinones and tricyclooxyisohumulones A and B as hard-resin components. These compounds are all oxidation products derived from 伪- or 尾-acids. We also investigated compositional changes in the hard resin during the wort boiling process, which has a significant effect on the taste of the beer, by using model boiling experiments. The major changes were identified to be isomerization of 4鈥?hydroxyallohumulinones into 4鈥?hydroxyallo-cis-humulinones, followed by decomposition into cis-oxyhumulinic acids. These findings will be helpful in systematically evaluating and optimizing the effect of the hard resin on beer quality.