Iso-α-acids

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Hydrogen peroxide accelerates the formation of such staling compounds as aldehydes and the degradation products of the iso-a-acids.[1]

Unhopped beers seldom develop an oxidized flavor, which suggests a likely role for the iso- α -acids as precursors of staling compounds ( Hashimoto et al., 1979 ). In model systems it has been shown that volatile carbonyls (alkenals and alkadienals with chain lengths of between 6 and 12 carbon atoms) can be produced from a solution of bitter substances, higher alcohols and melanoidins. The trans isomers are more prone to degradation than are the cis isomers ( De Cooman et al., 2000 ; Araki et al., 2002 ). Reduced side-chain iso- α -acids do not give staling carbonyls ( Hashimoto, 1988 ).[2]

See also[edit]

References[edit]

  1. Muller R. The formation of hydrogen peroxide during oxidation of thiol-containing proteins. J Inst Brew. 1997;103(5):307–310.
  2. Bamforth CW, Lentini A. The flavor instability of beer. In: Bamforth CW, ed. Beer: A Quality Perspective. Academic Press; 2009:85–109.