Y. HE (1), L. Chen (1), J. Dong (1), H. Yin (1); (1) State Key
Laboratory of Biological Fermentation Engineering of Beer, Tsingtao
Brewing Ltd., Qingdao, China
Poster
The ability of lager yeast, Saccharomyces pastorianus, to produce
a broad range of aroma-active compounds during fermentation is vital to
the final taste of beer. The lack of control over the production of
flavor compounds is a particular problem in modern high-gravity brewing,
which often leads to disproportionate amounts of higher alcohols and
volatile esters. In this study, normal-gravity and high-gravity wort
fermentations were compared and their impact on higher alcohols and
volatile ester production and expression level of related genes (BAP2, BAT1, BAT2, ATF1, ATF2, EEB1, EHT1 and IAH1) from both S. cerevisiae (Sc-type) and S. bayanus
(Sb-type) sub-genomes were evaluated. High-gravity brewing increased
both higher alcohols and volatile esters production, while the increment
of higher alcohols was almost three-quarters less than that of volatile
ester. In addition, the transcription level of all the higher alcohols
and volatile esters biosynthesis related genes were enhanced by
high-gravity brewing, except BAT2 (Sc- & Sb-), which was
involved into higher alcohol synthesis pathway. The results clearly
demonstrate that changes in flavor compound production in high-gravity
brewing appears to be due at least in part to transcription level of
genes involved in the biosynthesis process. This indicates that, for
high-gravity brewing, particular attention to the transcription of BAT2
genes should be paid to ensure proportionate amounts of higher alcohols
and volatile esters. The results offer the possibility of examining
gene expression in the context of fermentation progression to monitor
the concentrations of sensory metabolites in beer and control
fermentations.
Yang He is a scientist at the State Key Laboratory of Biological
Fermentation Engineering of Beer, Tsingtao Brewing Ltd. Most of her
research is related to beer flavor production during fermentation by
monitoring yeast gene expression. She received her Ph.D. degree in
marine science from the Ocean University of China in 2001.
View Presentation
Purchase and login is required to access presentations. Purchase access to the Proceedings.
