3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
tained about 14 µg g –1 of (–)catechin, 2 μg g –1 of rutin and
1.4 μg g –1 of caempherol, while wort contained about 5x
higher (–)catechin level. The ration of individual flavonoids
changed with malting temperature. Levels of flavonoids
changed similarly as phenolic content. TAS levels were several
times higher in dark types of malt than in wheat or Czech
malt.
Barley and malt proteins are relatively well-documented
and their analysis belongs to commercially used tests for barley
variety authenticity. Beer proteome has been not studied
in detail. In this work main protein fractions (40 kDa, lower
than 8–10 kDa, peptides – see Fig. 1. and Fig. 2.) were determined
in lyophillized beer samples. Pilot 2D electrophoretic
analysis of some beer samples was done mainly for optimization
of analysis conditions.
1 2 3 4 5 6 7 8 9 10
Fig. 1. 1D PAGE-SDS analysis of beer proteins. 1 – standard 6
(97.4, 67.0, 45.0, 29.0, 21.0, 12.5, 6.5 kDa; 3-7 – proteome from
lyofilized beer; 9 – standard 5 (29.0, 21.0, 12.5, 6.5 kDa); 10 –
standard 6
Conclusions
The aim of presented pilot study was to use modern
techniques to qualitative and quantitative analysis of characteristic
components of Czech beer. One of the main goals is
separation and analysis of specific proteins and peptide fragments
and changes of their content during beer processing.
Based on analysis of barley variety purity using standard 1D
s725
Fig. 2. Microfluidic 1D electrophoresis of beer proteins
PAGE-SDS detailed characteristics of proteins by microfluidic
techniques, 2D-electrophoresis, LC/ESI-MS, LC/MS/
MS was tested. Further aim was qualitative and quantitative
analysis of individual phenolics in Czech beer by chromatographic
techniques (RP-HPLC, LC/MS). All analyses will
be performed in several kinds of Czech beer in comparison
with beers processed by different technology. All results will
be compared to obtain a set of parameters suitable to final
characterization of Czech beer. This set could be used in food
control to authenticity assesment of Czech beer.
This work was supported by projects 2B08057 (National
Research Program II) of the Ministry of Education, Youth and
Sports of the Czech Republic and QH81056 of the Ministry of
Agriculture of the Czech Republic.
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