National Repository of Grey Literature 87 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Vývoj a rozmístění pěstování a produkce chmele ve světě
PAVLIŠOVÁ, Aneta
The bachelor thesis deals with the distribution of hops production and areas of hop fields according to the countries of the world and with the distribution of area of hop fields according to small districts of the Czech Republic. It also monitors the development of these distributions. In the introductory chapters of the thesis the hop literature and characteristics of hop as agricultural crop is given. Data for analyses comes from databases of the Food and Agriculture Organization - FAO (for countries) and the Czech land office (statistics for small districts), and they are transformed into resume tables, graphs and maps. In the long term, the largest hops producers in the world are the USA and Germany, with a considerable distance from the Czech Republic and China and, with a further distance from Poland and Slovenia. The number of hop countries is gradually decreasing and hops production is increasingly concentrated into the USA and Germany. The Czech Republic has the largest areas of hop fields in the Rakovník, Louny, Žatec and Podbořany small districts. The area of hop fields has decreased significantly in the Czech Republic.
Raw materials for beer production - history and present and their benefits for human health
NOHEJL, Vlastimil
This bachelor's thesis outlines the evolution of brewing from its outset to the present time. The aspects of production, processing, division, and composition of raw brewing materials are described in detail as well as the possibility of using alternative plant components to create non-traditional beers. The next chapter outlines the process of beer production with the emphasis on the individual technological operations and the importance of mashing temperatures. Since beer is a natural, nutritionally rich, fermented beverage, the final part of the thesis examines its health benefits.
Comparison of selected parameters of draft beers and lagers from breweries and microbrewery
HEJTMÁNKOVÁ, Zdeňka
The dissertation compares selected qualitative parameters beers on tap and lagers produced in large breweries and mini-breweries. The first part of the thesis briefly describes the basic raw materials for beer production. This is followed by a description of the production technology,which includes the production of malt and wort, fermentation and the finishing of beer. The practical part of the dissertation describes selected types of beer. Values obtained from a component analysis of beers are evaluated in tables and graphs. Individual beers are assessed mainly according to the alcohol content (% vol.). The difference between the microbrewery and large breweries was insignificant. The work includes sensory evaluation of selected samples. Taste, aroma, opacity, carbonation and bitterness of beers are assessed. The best rated beer in the sensory rating was Samson BOCK. From the mini-brewery Čtyrák 12 ° light premium lager beer was the best.
Pests and diseases of hop - factual information database and e-learning system
KOVAŘÍK, Michal
This work deals with making factual database for crop Humulus lupulus L. The information, contained in the database falls within the protection of plants and more specifically to the field phytopatological, entomological and phytosanitary. Literature research provides an overview of the issue and information technology. The database has been compiled in the years 2007 - 2009 and the idea is to create a system for diagnosis and effective source of information for plant protection. For the creation of databases and educational system have been used languages PHP, HTML and cascading style sheets to format the graphic. For the purposes of the database was used by the SQL language and relational version of MySQL. The system is a detailed description, bionomics and protection. The system also contains a considerable number of pictures. The results are presented as a guide for working with the system.
Pretreatment of hops for further processing in beer technology
Tichá, Anna ; Štursa, Václav (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis deals with pre-treatment of hops for further processing in beer technology. In the experimental part of the work, the effect of low temperatures, as pre-treatment of hops, on the monitored parameters was observed. Three types of cold pretreatment were used. In two cases, the hop material was frozen using a freezer at -25 ° C and in the second case at -70 ° C. In the third case, the hop material was treated by contact with liquid nitrogen in combination with mechanical treatment. The variety of hop materiál was Žatecký poloraný červeňák, which were in the form of pellets or pressed hop cones. The total bitterness of the samples, the total content of phenolic substances, the total content of flavonoids, the antioxidant activity and the concentration of essential oils, specifically myrcene humulene and geraniol, were examined. The effect of pre-treatment was investigated during conventional worth boiling as well as dryhopping. The experimental part includes descriptions of the hopping process, descriptions of individual analytical methods. A parallel measurement was performed on each sample. Significant advantages or disadvantages of some of the pretreatments were not demonstrable, however, the most significant differences were observed in samples hopped with hops pretreated by freezing at -70 ° C, which had a positive effect on the amount of extracted essential oils during cold hops.
Bioflavouring of beer using new Czech hop varieties
Ondruch, Petr ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis focuses on bioflavouring of beer using new czech hop varieties. Dry hopping is a phenomem, that contributes to the attractiveness and diversity of beer and is nowadays gaining in popularity. The aim of this work was to determine the effect of dry hopping on sensory profile and analytical parametrs of dry-hopped beers using czech hop varieties. Sensory evaluation and chemical analysis of these beers were taken. The chemical analysis included determination of the basic beer characteristics, total phenolic a flavonoid content, antioxidant activity and the concentration of selected organic acids and chemical elements. It was found out that dry-hopped beers compared to the reference beer presented higher bitterness, antioxidant activity and contained higher amount of flavonoids. Also an increase in pottasium, manganese, copper, calcium and malic acid levels was reported. The pH of beer samples was not affected by dry hopping. Sensory evaluation showed that dry hopping had a positive influence on the overall enjoyment of the beer, which was mainly determined by the higher aroma and more intense bitterness. By summaring all the data, it is obvious that dry hopping of beer using new czech hop varieties has a positive effect on the quality of the final beer and these hop varities are suitable for further use in the beer industry.
Effect of the dry hopping of the stability of beer foam
Benda, David ; Štursa, Václav (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis deals with the influence of dry hopping on the stability of the beer foam. It was observed how this effect affected general characteristics of beer, the content of hop bitter acids, proteins, phenolic compounds, selected micro- and macro elements, organic acids and the stability od the beer foam. Theoretical part characterises raw the materials for beer production, the substances affecting the stability of beer foam and the beer brewing process. Furthermore the beer foam is described froam a physical point of view together with the steps of its formation and drainage as well as other phenomena that lead to its disappearance. A detailed description of used analytical methods is included. The experimental part illustrates the preparation of the model beer and the implementation of dry hopping with the Czech hop variety called Kazbek. Dry hopping was carried out on day 3, day 5 and day 10 with a 3 g/l and a 6 g/l hop dose. The prepared beer was subsequently analysed for general characteristics, the beer foam stability, bitter hop acids, phenolic compounds, protein, selected micro- and macroelements and organic acids. Based on the measured data, there were found correlations between the observed beer parameter and the stablity of the beer foam. The results revealed that dry hopping in beer increases the content of the phenolic compounds and bitter substances, but its effect on the beer foam stability is negative.
Characterization of new czech hop varieties
Faruzel, Vojtěch ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
In this thesis the problem of characterization of new Czech hop varieties was investigated. The selected new varieties were Mimosa, Jazz and Blues. Their composition was compared with the widely used varieties Žatecký poloraný červeňák and Kazbek. The content of -bitter acids and -bitter acids, total phenolic content, flavonoid content and antioxidant activity were determined by UV-VIS spectroscopy for all hop varieties. The composition of hop essential oils was estimated by SPME-GC-MS. The diversity of the hop varieties was confirmed from the measured data by statistical analysis. The new varieties showed statistically significant differences in all monitored parameters, especially in comparison with the varieties Žatecký poloraný červeňák and Kazbek. The quantitatively different representation of -bitter acids and -bitter acids has an influence on the character and intensity of bitterness of these hop varieties. The composition of the hop essential oils, the content of phenolic substances, flavonoids and antioxidant activity are reflected in the different organoleptic properties of the hops analysed and of the beer.
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...
Pharmacologically active compounds in hops
Pýchová, Kateřina ; Cvrčková, Fatima (advisor) ; Mašková, Petra (referee)
The hop plant (Humulus lupulus) is used not only in brewing but also in phytopharmacology and phytotherapy. Among the isolated or chemically produced substances used for healing are xanthohumol, 8-prenylnaringenine and α and β-bitter acids. Nowadays, a lot of attention is paid to their effect on humans - especially to their anticancer activity. But there is a lack of information about the importance of these substances for the hop plant itself. Most of the plant secondary metabolites originally serve for protection of the plant against pathogens and herbivores. The selected metabolites are not an exception. The purpose of this work was to summarize the published data about the biological importance of selected hop secondary metabolites and the effects they have on other organisms than plants, with an emphasis on humans.

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