L. A. GARBE (1), N. Rettberg (1), M. Mengdehl (2), M. Pueschel (1);
(1) VLB Berlin, Berlin, Germany; (2) TU Berlin, Berlin, Germany
Stability
Wednesday, June 4 - 3:00 p.m.-4:45 p.m.
Level 3, Crystal Room
More than 50 years ago, in 1962, MacLeod and White suggested, that
“trace materials derived from lipids may offer a significant
contribution to the complex mixture of trace substances affecting the
organoleptic qualities of beer.” In 1971 Drost et al. proposed that an
oxygenated derivate of linoleic acid, i.e.,
9,12,13-trihydroxy-10E-octadecenoic acid, is the precursor of the
dreaded cardboard flavor contributor, trans-2-nonenal, in beer.
In the following years extensive research on beer flavor stability has
been carried out, and chemical and enzymatic factors that influence
lipid breakdown and formation of oxygenated fatty acids during beer
production and storage have been investigated. Indeed the formation of
trihydroxy fatty acids (THOE) is an indicator for lipoxygenase activity
and autoxidation processes during malting and mashing. However, a causal
correlation between THOE and trans-2-nonenal has never been
evidenced. The current paper comprehensively reviews the milestones of
50 years of research in regard to THOE, a highly relevant topic lacking
in accessibility to many brewers. It draws a clear line between the
myths and the facts that surround the role of oxygenated fatty acids in
brewing. The review is supplemented by our own updated experimental data
on THOE from wort and beer. Here, the focus is on beers brewed using
alternative starch sources such as corn, rice, and adjuncts. The
analysis of barley malt worts and low LOX malt worts shows remarkable
shifts in concentration, especially isomeric distribution of THOE.
Future trends in THOE analysis, triggered by recent improvements in
analytical instrumentation, are discussed.
Leif-Alexander Garbe is a professor of applied chemistry at the
University of Applied Science Neubrandenburg, Germany. In addition, he
is a visiting professor at the Berlin Institute of Technology (TU
Berlin) and also head of the Research Institute for Special Analysis at
VLB Berlin. Leif graduated from TU Berlin with a diploma in chemistry in
1996. From 1996 to 2002 he worked on his Ph.D. thesis and received his
in 2002 from the Institute of Biotechnology, TU Berlin. In 2002 he
established a new research group at TU Berlin focusing on
biotransformation, isotope dilution techniques, and Maillard reaction of
peptides/proteins. His VLB Institute for Special Analysis was also
founded in 2002. From 2008 to 2009 he was a visiting professor at TU
Berlin. As of January 2014, Leif is a professor of applied chemistry in
the School of Food Technology in Neubrandenburg. Leif has authored more
than 40 original scientific publications, more than 10 book chapters,
and more than 100 oral and poster presentations related to chemistry and
biotechnology within the last 15 years.
