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Chmelové silice a možnosti jejich využití
Pokorná, Tereza
Hops is one of the basic raw materials for beer, but it can be used not only for beer very noteworthy are his healing abilities. Czech Saaz variety belongs to among the best hops in the world, whose quality is involved in both genetics and climate. In addition to the substances important to the taste and aroma of beer, it contains a number of other substances with health significance. The aim of this work was to determine the essential oil content in hop cones and pellets. Specify the content of selected components of essential oils and statistically evaluate differences in their content. In the literature to find healing effects of hops and hop possibility of using essential oils. The results show that a very significant effect was high variety on the total content of essential oils and essential oils into individual components (myrcene, caryophyllene, farnesene and humulene). The highest essential oil content was detected in samples of dried hop cones of Saaz hops variety recuperation forms (525 ul.100 g-1), while the lowest essential oil content was detected in samples of dried hop cones unrecuperation forms variety Saaz variety (295 ul.100 g-1) . Dried hop cones are demanding storage and dispensing. Hop pellets are most commonly used because they are easily dosed and stored.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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