Sensory Session
Caroline Scholtes, Université catholique de Louvain, Earth and Life Institute (ELIM), Louvain-la-Neuve, Belgium
Co-author(s): Masatatsu Shiba, Asahi Breweries Ltd., Ibaraki, Japan;
Thomas Haube, Sabrina Nizet, and Sonia Collin, Université Catholique de
Louvain, Earth and Life Institute (ELIM), Louvain-la-Neuve, Belgium
ABSTRACT: Volatile phenols are responsible for spicy notes
in a large range of beverages. Various flavor active phenolic compounds
have been detected in beer. Among them, 4-vinylguaiacol and
4-vinylphenol are well known to release clove-like flavor in Belgian
white beers made with unmalted wheat. In many other top fermented blond,
amber, and brown beers, phenols also determine the overall flavor
perception. In the present work, phenol-specific extracts of 14 Belgian
special beers were investigated by gas chromatography-olfactometry
(GC-O/AEDA methodology) and gas chromatography-mass spectrometry
(GC-MS). Different profiles were highlighted according to the raw
materials used (special malt, organic malt, wheat), yeast strain, or
maturation vessel. 4-Vinylphenol, 4-vinylguaiacol, and vanillin were
found well above their respective thresholds in beers produced with
highly Pof+ yeast. On the other hand, a low ethyl/vinyl ratio was found
in brands where Brettanomyces strains are used for secondary
fermentation, bottle refermentation, or cask maturation. Finally, two
original phenols emerged as interesting markers, allowing us to
authenticate the use of torrefied/chocolate malts.
Graduating
in 2007 as a bio-engineer from Catholic University of Louvain (Belgium),
Caroline Scholtes completed her education in 2008 with a master’s
degree in brewing science. In 2010, she started a Ph.D. program at the
same university. Her research focuses on aging of Belgian special beers
with regard to raw materials, brewing process, and storage conditions
and correlates this to modification of organoleptic profile, especially
Madeira off-flavor and volatile phenols. She is also a teaching
assistant in beer chemistry at the same university.
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