Английская Википедия:Isohumulone

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Isohumulones are chemical compounds that contribute to the bitter taste of beer and are in the class of compounds known as iso-alpha acids. They are found in hops.

Beer

The bitterness of beer is measured according to the International Bitterness Units scale, with one IBU corresponding to one part-per-million of isohumulone. When beer is exposed to light, these compounds can decompose in a reaction catalyzed by riboflavin to generate free-radical species by the homolytic cleavage of the exocyclic carbon-carbon bond. The cleaved acyl side-chain radical then decomposes further, expelling carbon monoxide and generating 1,1-dimethylallyl radical. This radical can finally react with sulfur-containing amino acids, such as cysteine, to create 3-methylbut-2-ene-1-thiol, a thiol which causes beer to develop a "skunky" flavor.[1]

Formation

Isohumulones are generated by the isomerization of humulone.[2][3][4]

Файл:S-Humulone Isomerization.svg
Isomerization of humulone to cis- and trans-isohumulone

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See also

References

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  1. Шаблон:Cite web
  2. Ошибка цитирования Неверный тег <ref>; для сносок ReferenceA не указан текст
  3. Шаблон:Cite journal
  4. Esslinger, H. M. and Narziss, L. 2003. “Beer.” in Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag GmbH & Co. KGaA, 2009 Шаблон:Doi