Abstract The evolution of isohumulones, main bitter compound of beers, through storage and its bitter impact has been studied for many years. With the uprising of highly hopped and, especially, dry-hopped beers during the last decade, other compounds such as humulones, cis-humulinones and hulupones have been shown to participate in both the sensory and measured bitterness of these beers. However, the fate of these compounds through aging is still unclear. The present work evaluated, by means of spectrophotometric and RP-HPLC-UV analyses, the evolution of bitterness units (BU), cis- and trans-isohumulones, humulones, cis-humulinones, hulupones, and tetrahydro-isohumulones in 21 Belgian dry-hopped beers after two years of storage. Besides the expected degradation of trans-isohumulones, it was observed an average decrease of 91% of humulones and 73% of cis-humulinones. Together, these results indicate a decrease of 18 – 43% of the calculated bitterness intensity of dry-hopped Belgian beers. The losses of cis-humulinones in dry-hopped beers bring seven new oxidation compounds, some of them very similar to those issued from trans-isohumulones. The bitterness impact of these compounds is yet to be determined.

中文翻译：

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通过干啤酒花陈酿苦味化合物的命运。为什么顺式葎草酮应该像反式异葎草酮一样令人恐惧？

摘要 啤酒的主要苦味化合物异葎草酮在贮藏过程中的演变及其苦味影响已被研究多年。随着过去十年中高度啤酒特别是干啤酒花啤酒的兴起，其他化合物如葎草酮、顺式葎草酮和葎草酮已被证明参与了这些啤酒的感官和测量的苦味。然而，这些化合物在衰老过程中的命运仍不清楚。目前的工作通过分光光度法和 RP-HPLC-UV 分析评估了 21 个比利时干果中苦味单位 (BU)、顺式和反式异葎草酮、葎草酮、顺式葎草酮、葎草酮和四氢异葎草酮的演变。存放两年后的啤酒。除了预期的反式异葎草酮降解外，观察到平均减少了 91% 的葎草酮和 73% 的顺式葎草酮。总之，这些结果表明干酒花比利时啤酒的计算出的苦味强度降低了 18-43%。干啤酒花啤酒中顺式葎草酮的损失带来了七种新的氧化化合物，其中一些与反式异葎草酮产生的非常相似。这些化合物的苦味影响尚待确定。