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P 012
Analysis of flavor active carbonyls
in beer by derivatization with 2,4-dinitrophenylhydrazine
and HPLC-
ESI-MS/MS
P 013
Evaluation of chemical physical
stability of craft beers through
unconventional methods
P 014
System and method for on-line
monitoring of beer primary fermentation
based on UV-VIS-SWNIR
spectroscopy
Nina Baumjohann 1 , Diedrich Harms 1
1VLB Berlin e.V., Central Laboratory, Berlin, Germany
Stefano Bertoli 1 , Stefano Buiatti 1 ,
Paolo Passaghe 1
1University of Udine, Department of Food Science, Udine, Italy
Pedro Rodrigues 1 , Tiago Brandão 1 , Rui M.C.
Martins 2,3 , José A. Teixeira 3 , Eurico Seabra 4 ,
Luis F.F. Silva 4 , Antonio A. Vicente 3
1Unicer Bebidas, SA, S. Mamede Infesta, Portugal, 2 Universidade
do Minho, CBMA - Molecular Biology and Environmental
Research Center, Braga, Portugal, 3 Universidade do Minho,
IBB - Institute for Biotechnology and Bioengineering, Centre
of Biological Engineering, Braga, Portugal, 4 Universidade do
Minho, CT2M - Centre for Mechanical and Materials Technologies,
Guimarães, Portugal
DESCRIPTION OF TOPIC:
During beer aging plenty of flavor active
carbonyls are formed by different degradation
processes. Due to their very low concentrations
affecting the quality of beer (e.g.
2-(E)-nonenal) a sensitive analysis method is
needed. The aim of this work is to develop a
robust option for the determination of flavor
active carbonyls as addition or alternative to
laborious GC-MS routine analysis methods.
After a preliminary matrix separation, a selective
derivatization of carbonyls is effected
by the use of the reagent 2,4-Dinitrophenylhydrazine
(2,4-DNPH). For a sensitive determination
of the formed derivatives high performance
liquid chromatography coupled with
electrospray-ionization and tandem mass
spectrometry (HPLC-ESI-MS/MS) is used. By
applying the multiple reaction monitoring
(MRM) the selectivity is increased. Additionally,
unexpected or unknown carbonyls can
be discovered by the use of different mass
spectrometric experiments.
DESCRIPTION OF TOPIC:
Aims: The aim of this work was to evaluate
the colloidal stability of beers correlating EBC
methods (sensitive proteins and Chapon test)
to gluten content and antioxidant activity (AA).
Methods: Three beers with different formulations
were produced: the reference one 100%
malted barley, the other two with increasing
amounts (20 and 40%) of buckwheat. Chemical
physical stability was evaluated using four
indices: sensitive proteins, alcohol chill haze
test, gluten content and antioxidant activity. T-
test was applied for statistical analysis.
Results: Both gluten analysis and antioxidant
activity measurements showed a correlation
with data obtained with EBC methods.
Conclusions: The analysis of gluten and AA
may be used as qualitative and predicitive
indexes of stability being more specific than
sensitive proteins and Chapon test. The use of
gluten free adjuncts could lead to more stable
final products with a gluten content less than
100 mg/L.
DESCRIPTION OF TOPIC:
Aim: This work aims at demonstrating a new
system and method for on-line monitoring of
beer primary fermentation.
Methods: The system is based on UV-VIS-
SWNIR spectroscopy. It includes: 1) a fiberoptic
probe and a universal probe adaptor
specially designed for industrial fermenters;
2) a mini-spectrometer; 3) software specially
developed for multivariate calculation of fermentation
parameters; 4) graphical interface.
Results: Calibrations were developed for biomass
(CFU/mL), Brix, pH, ethanol (%), color,
apparent and real extract (%), RDF (%), ADF
(%), n-propanol (mg/L), iso-butanol (mg/L), total
amyl alcohols (mg/l), ethyl acetate (mg/L),
amyl acetate (mg/L), acetaldehyde (mg/L),
dimethyl-sulfate (mg/L); diacetyl (mg/L).
Correlation factors were always above 0.92.
On-line calculation of these parameters was
performed.
Conclusions: The system is able to perform
real-time and predictive control and diagnostics
of beer fermentations, allowing preventive
or corrective measures.
Nina Baumjohann
Stefano Bertoli
Pedro Rodrigues
Nina Baumjohann studied food chemistry
at the University of Münster and graduated
as a certified food chemist. Since 2010 she
has been working as a scientific assistant in
the Central Laboratory of the Research and
Teaching Institut for Brewing in Berlin.
Stefano Bertoli was born in Udine in 1982,
he got the degree in Food Science and Technology
at the University of Udine, Italy. After
some experience as a brewer, gained in Italy
and abroad, he is now working with Prof.
Buiatti at the Department of Food Science as
brewmaster and coordinator of the activities
of beer production and on the optimization of
production techniques of craft beer and evaluation
of chemical and sensory properties of
finished product. In addition, he serves as brewery
manager at the Birrificio Udinese.
Pedro Rodrigues was born at Oporto, in 1973.
In 1996 took the degree in Biochemistry and
in 2003 a PhD. in Chemistry, both in Oporto
University. From 1996 to 2004, works in research
within Oporto University, and in 2001
at BRI, where builds up his passion for beer.
Since 2004 works for Unicer, passing through
different positions in Quality & Innovation
Dept. as manager, first in the central lab, in
central technical services and finally in industrial
quality. In 2011 was appointed as production
director.
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