Kvasny Prumysl, 2010 (vol. 56), issue 11-12
Possibilities of utilization of modern sample preparation methods for gas chromatographic analyses in beverage and namely brewing analytics. Part III. - Solid-phase microextraction and stir bar sorptive extraction in fatty acids analysis in beer.Peer-reviewed article
Tomáš HORÁK, Jiří ČULÍK, Marie JURKOVÁ, Pavel ČEJKA, Vladimír KELLNER, Josef DVOŘÁK, Danuša HAŠKOVÁ
Kvasny Prum. 2010; 56(11-12): 418-422 | DOI: 10.18832/kp2010042 
Solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE) are modern and simple sample preparation procedures. This study is focused on utilization of these techniques for the determination of fatty acids in beer. While from the coated fiber of the SPME analytes were thermally desorbed in the hot injector of the gas chromatograph equipped with a fused silica capillary column ZBWAX and a flame ionisation detector thus in SBSE procedure analytes were desorbed by solvent back extraction and then analysed by gas chromatography. Working parameters and advantages together with limitations of both sample preparation methods are shown.Solid-phase...
The relationship between barley starch content and malt extract.Peer-reviewed article
Ivo HARTMAN, Josef PROKEŠ, Alena HELÁNOVÁ, Jiří HARTMANN
Kvasny Prum. 2010; 56(11-12): 423-427 | DOI: 10.18832/kp2010043
Barley samples from harvest 2005-09 were evaluated. Samples with high and low starch content were malted and malt extract was determined. The aim was to assess the relationship between a previous crop, barley yield, sieving fractions over 2.5 mm, barley technological quality and starch content and further to determine the effect of starch content on malt yield, malt extract and theoretical extract yield in malt per hectare. Starch content affected statistically significantly extract content in malt and thus also extract yield per hectare. Statistically highly significant negative correlation between the content of nitrogenous substances and starch...
Determination of Trans-2-Nonenal in Barley Grain, Malt and Beer.Peer-reviewed article
Zdeněk SVOBODA, Renata MIKULÍKOVÁ, Sylvie BĚLÁKOVÁ, Karolína BENEŠOVÁ, Ivana MÁROVÁ, Zdeněk NESVADBA
Kvasny Prum. 2010; 56(11-12): 428-432 | DOI: 10.18832/kp2010044
Trans-2-nonenal is an aldehyde contributing to an unpleasant off-flavor and odor of rancid butter in stored beer. The aim of this study was to optimize and introduce automated solid phase microextraction technique coupled with gas chromatography for determination of trans-2-nonenal in beer and brewing materials. Five types of SPME fibers coated with different stationary phases (100 μm PDMS, 65 μm PDMS/DVB, 85 μm CAR/PDMS, 50/30 μm DVB/CAR/PDMS, 85 μm PA) were tested for their efficiencies in the headspace SPME. The highest HS-SPME extraction efficiency was achieved with the PDMS/DVB fiber and addition of 1.5 g of NaCl, extraction...
Quality of barley grain from testing sites of the Czech Republic, harvest 2009.Peer-reviewed article
Vratislav PSOTA, Lenka SACHAMBULA, Olga DVOŘÁČKOVÁ
Kvasny Prum. 2010; 56(11-12): 433-438 | DOI: 10.18832/kp2010045
Samples of three varieties of spring barley from 23 testing stations and two winter barley varieties from 14 testing stations were analyzed according to the standard ČSN 461100-5. The favorable course of weather in 2009 positively affected content of nitrogenous substances (11.8 % and 11.7 %) and starch (63.8 % and 63.8 %) in spring and winter barley caryopses. The occurrence of sprouted grains was minimal and the amount of the damaged grains was low. Grain harvested in 2009 was bigger and its size was homogenous. Portion of sieving fractions above 2.5 mm was on average 87.5 % in spring barley and 94.0 % in winter barley. Year 2009 was a favorable...
Post harvest maturation of the selected spring barley varieties in 2009.Peer-reviewed article
Lenka SACHAMBULA, Vratislav PSOTA
Kvasny Prum. 2010; 56(11-12): 439-444 | DOI: 10.18832/kp2010046
In harvest year 2009 lower values of germinating energy three weeks after achieving full ripeness were recorded. Values of germinating energy after achieving full ripeness exceeding 95 % were recorded only in the varieties Aktiv and Jersey. Varieties exhibited considerable differences in intensity of germination, i.e. rate and index of germination. Nine weeks after achieving full ripeness the varieties Henley, Publican, Radegast, Signora, Vista, and Xanadu germinated quickly and readily unlike the varieties Advent, Aksamit, Aktiv, Marthe, Streif, and Tolar. Variability of germinating energy was affected by the location, variability of characters describing...