National Repository of Grey Literature 21 records found  previous11 - 20next  jump to record: Search took 0.00 seconds. 
Determination of biologically active compounds in hops by LC/HR-MS method
Jandovská, Vladimíra ; Sobotníková, Jana (advisor) ; Spáčil, Zdeněk (referee)
This thesis describes development and optimalization of method for identification of polyphenols compounds present in hops (Humulus lupulus L.) that have potential antimicrobial activity. Within extraction of compounds from hop, minced hop cones were applied in a growth medium, where compounds diffused into the medium and created an inhibition zone after inoculated with Streptococcus aureus. The method combining extraction with acetone a salting out using QuEChERS principles was optimized for extraction of compounds from solid growth medium. The analysis was carried out using LC/HR-MS with a quadrupole-orbitrap hybrid mass analyzer. The MS method was developed as a screening method with a subsequent fragmentation of compound of interest on the base of inclusion mass list. The compounds extracted from inhibition zone were identified either by searching against a database or their structures have been elucidated on the basis of their fragmentation spectra.
Analysis of polyphenolic compounds in selected brewery matrices by HPLC-HRMS method
Zušťáková, Veronika ; Sobotníková, Jana (advisor) ; Mikyška, Alexandr (referee)
The thesis has focused on the separation of proanthocyanidins (Pas) in beer, raw beer material and beer intermediates (wort, hopped wort, green beer) by using high performance liquid chromatography coupled to high resolution mass spectrometric detection. A chromatographic column XSELECT HSS T3 was used for separation of individual proanthocyanidins. Mobile phase was formed by a mixture of 0,1% formic acid in water (A) and 0,1% formic acid in acetonitril (B), separation was conducted in gradient mode. Calibration range for catechin and procyanidin B1 a B2 was linear in the range from 10 µg.l-1 to 200 µg.l-1 and for epicatechin from 5 µg.l-1 to 200 µg.l-1 . Limit of quantitation (LOQ) was set to the lowest point of calibration curve, hence for catechin, procyanidin B1 and B2 was LOQ = 10 µg.l-1 and for epicatechin was LOQ = µg.l-1 . Yield of method of the observed Pas was very good, where yield oscillated around 100%. The method also had excellent repeatability, where the relative standard deviation (RSD) was lower then 20%. After optimization of this method it was used for observation of profile changes during brewery process in catechin, epicatechin, procyanidin B1, B2 and B3. It was discovered, that catechin, epicatechin, procyanidin B1 and B2 originate mainly from hops and procyaniding B3 is...
Hops harvest phenomena in socialist Czechoslovakia
Verner, Jiří ; Rychlík, Jan (advisor) ; Randák, Jan (referee)
The aim of this thesis is to introduce hops harvest phenomena as a special kind of agriculture aid in socialist Czechoslovakia. The aid consisted of secondary school students in the 1960s. The thesis describes organization of hops harvest, process of harvesting work and after-work activities of temporary staff. This thesis contains occurrences of August 1968 in Czechoslovakia. The harvesting work was complicated by raid of Soviet Army in this year.
Evaluation of hop quality from traditional and non-traditional region of cultivation
In this thesis, "The Evaluation of the Quality of Hops from Traditional and Non-traditional Growing Areas", the quality of three varieties of hop seed cones (Saaz, Sladek and Kazbek) from a non-traditional hop-growing region was analyzed and the data used for comparison. The primary aim of the study was to determine if there is a possibility of growing quality hops in a region that is not considered a hop-growing region. The hops that were tested were harvested in 2015 from a private hopfield located in Obora near Tábor. This hopfield is owned and managed by Ing. Martin Novák. Mechanical and chemical analysis was carried out on samples from Obora. The main goal of the analysis was to determine the alpha and beta acid content of the hop seed cones harvested there. Samples were analyzed with EBC 7.7 (HPLC). Alpha acid content of the tested samples in Saaz hops was 4.06 % w/w, in Sladek 7.14 % w/w and in Kazbek 4.67 % w/w. The content of beta acids in Saaz hops was 3.16 % w/w, in Sladek 3.93 % w/w and in Kazbek 4.51 % w/w. The collected data was then compared to published data for hops grown in traditional hop-growing regions. Alpha acid content was found to be higher in the hops grown in Obora, while beta acid content was lower.
Historical Breweries: the Past or the Future?
Mosler, Štěpán
Until these days we have registered 1400 brewery facilities. In this list there are factories which are fully functional, used for another function, abandoned or completely vanished. Unfortunately most of them are ruins or completely destroyed. Important thing is how we will treat with these structures in the future. Will we use this unique potential, or leave this place for a new function? Which way we can choose? What is the potential of these buildings and what they need? This article tries to briefly describe and highlight the extraordinary qualities of a large group of industrial buildings which due to dramatic changes in society became endangered.
Brewery in Buštěhrad: student competition as an accelarator of monument preserve
Mosler, Štěpán
Nowadays there are hundreds of breweries scattered throughout Bohemia, Moravia and Silesia, waiting for their new future. They are either abandoned or in private property. In the worst case they have been deteriorating with no hope of recovery. There are
History and development of the brewery architecture
Mosler, Štěpán
This thesis attempts to briefly describe historical context and evolution of brewery architecture in the Czech, Moravian and Silesian countries. Focused on the main milestones, which affected development of brewing architecture from beginning’s to the present.
Cultivation of hops (Humulus lupulus L.) and its use
Hop differs from other agricultural plants in view of the fact that it is a perennial plant. It can grow at one site up to 20 years. There are three recognized hop production areas in the Czech Republic such as Žatecko, Úštecko and Tršice. The quality of the cones is high mainly due to the range of plant variety and also due to the favourable environmental conditions. Hop cultivation technology was already explored a long time ago, and therefore the new resources are rarely available and also widely scattered. The aim of this thesis is to describe the hops cultivation technology and its food and non-food utilization. This work includes botanical characteristics, farming techniques, fertilization, and protection against pests, harvest and post-harvest treatment. Furthermore there is description of the influence of agricultural engineering or fertilization on quality of hops. This bachelors thesis also depicts food and non-food use of hops.
Optimization of the hop harvest in relation to maximizing product quality indicators
The thesis analyses and evaluates content and composition of bitter acids by HPLC method and Hop Storage Index (HSI). These methods were applied on samples taken from four varieties of hop (Saaz, Brewer, Premiant and Agnus) in four locations (Blšany, Běsno, Nesuchyně and Strojetice) of žatec hop-growing area in the period from 18. 8. 2012 to 4. 9. 2012 during the hop harvest. Furthermore, the influence of the drying procedures on the hops was monitored, it means, difference in the content and composition of bitter acids between green and dry hops and the comparison between the band and chamber drying rooms.
The quality of raw materials for beer production
SOUČEK, Martin
The subject of the thesis "The quality of raw materials for beer production" is a quality brewing ingredients - barley malt, malt, hops, water and brewer's yeast. Individual ingredients are generally characterized. The main part of the thesis deals with the assessment of quality of raw materials according to various criteria such as the genetic basis, agroecological factors, and technological requirements. The paper also discusses the methods of measurement quality.

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