|
|
Monitoring the stability of the beer brewing process
Tichá, Anna ; Štursa, Václav (referee) ; Diviš, Pavel (advisor)
The bachelor thesis deals with the analysis of 3 samples of the same beer, brewed in different batches of the brewing process. The analyzed sample is Dalešická jedenáctka - light lager of 11% of the Stock Brewery Dalešice, a.s., which was taken directly from the lager tanks in the brewery. The aspect we have examined were total protein content, total carbohydrate content, maltose content, total polyphenol content and ethanol content. The Hartree-lowry method was used to analyzed the total protein content. Total carbohydrates were measured spectrophotometrically using anthrone reagent. The maltose content was analysed by HPLC with an ELSD detector. The total polyphenol content was analyzed by the Folin-Ciocaltau reagent method and measured spectrophotometrically. The ethanol content was analyzed on a HPLC using a refractometric detector. The aim of the work was to compare to what extent the process of beer production is stable and what parameters may change in the final product
|
|
|
The laboratory control of beer
Klinková, Lucie ; Pařilová, Kateřina (referee) ; Omelková, Jiřina (advisor)
This bachelor thesis is aimed on laboratory monitoring of raw materials for beer production, in-process monitoring and final product control. Theoretical part deals with variety of procedures needed to produce a quality final product. Practical part of thesis was done in a laboratory of a medium sized brewery in the Czech republic. The production of formentioned brewery is 300, 000 hectolitres of traditionally brewed beer per year. The quality control of wort and final product was done. In – process control was done to obtain the extract value and pH of wort. The clarity, color, pH, gravity, and the both apperental and real alcohol content, the degree of attenuation of apperental and real content of bitter substances was determined in final product.
|
|
|
Changes of gluten proteins during beer processing
Porubiaková, Otília ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
The aim of thesis was monitoring of changes in the content of gluten proteins in the biotechnological process of beer production. During the production process of wheat and barley beer, the samples were collected and analysed using the electrophoresis and immunoassay method. The results of the analyses were compared with commercial Czech beers. The theoretical part contains description and composition of gluten proteins, malt and beer technology, the changes that occur in this process, and methods of gluten proteins analysis. The experimental part contains procedures for laboratory production of barley and wheat beer and analyses of gluten proteins. To identify the individual gluteal protein fraction acid and SDS electrophoresis methods were used. For quantification, enzyme immunoassay was used and evaluated spectrophotometrically. The identification of the gluten‘s fractions by electrophoretic methods has been shown to be less specific for samples with lower content of gluten proteins and for barley specimens. A decrease in the concentration of gliadins and glutenins in the beer production process was demonstrated. A significant change was found during wort production with 98% decrease of gluten content compared to the feedstock and during the fermentation, when the gluten concentration dropped below 10 mg/kg. This value is acceptable from the legislation for products labelled „gluten-free“.
|
|
|
Monitoring of 3-MPCD content in barley, malt and beer
Šálková, Michaela ; Svoboda, Zdeněk (referee) ; Mikulíková, Renata (advisor)
The master’s thesis focuses on a process contaminant 3-MCPD (3-chloropropane-1,2-diol), which is formed during food processing. The first part of the thesis summarizes scientific knowledge about its chemical and physical properties, toxicity, occurrence in food and methods of analysis. In the second part is monitored the content of 3-MCPD in barley, in standard and special types of malts and beer. Samples were derivatized with phenylboronic acid (PBA) and 3-MCPD derivatives were analyzed by gas chromatography with a mass detector. Deuterated 3-MCPD was used as an internal standard. The limit of quantification was 1 gkg-1 for barley and malt samples and 10 gkg-1 in case of beer. The barley samples contained concentration of 3-MCPD below LOQ. In samples of malt was found concentration
|
|
|
Sensory quality of chosen types of beer
Lišková, Michaela ; Divišová, Radka (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the sensory guality of chosen types of beer. The teoretical part was focused on the production of malt and beer and raw materials needed and also an introduction to sensory analysis was described. The experimental part was focused on evaluation itself. Nineteen untrained assesors were invited for sensory evaluation, who evaluated five selected beer kinds using the preprepared form. Unstructured graphic scale with a verbal description of anchor points was used to evaluate the appearance and color, taste and odour, fullness, bite, foaming, bitterness and any off-taste or off-odour of each sample. Five-point category ordinal scale was used for assessment of the overal acceptability of the samples. Results of the analysis were then evaluated graphically and statistically.
|
|
|
The determination of mycotoxins in commercial beers
Martiník, Jan ; Benešová,, Karolína (referee) ; Mgr. Marek Pernica, Ph.D (advisor)
Mycotoxins are secondary metabolites of microscopic fibrous micromycetes that are able to infect cereals. The use of contaminated materials can lead to transfer of mycotoxins into the final product, such as beer. The master’s thesis deals with the determination of mycotoxins in beers. The theoretical part of this thesis describes selected mycotoxins, their occurrence, toxic properties and legislative limits of the European Union. The theoretical part also deals with the description of beer production and the possibilities of mycotoxin determination. The theoretical part also describes the statistical methods used for data processing. The experimental part of this work describes the validation of the method for determination of mycotoxins in beers. This section also describes the optimization of mycotoxin extraction using a commercially available 11+Myco MS-PREP® immunoaffinity column. The conditions for the determination of mycotoxins on UPLC-MS/MS are given in this thesis. The validation parameters such as linearity, accuracy, precision, LOD and LOQ were determined. This section contains a description of beer samples used for the determination of mycotoxins. The goal of the thesis was to optimize and validate the method for determination of mycotoxins in beers. From the validation parameters, it was found that this method is suitable for its intended purpose, namely for mycotoxins aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, fumonisin B1, fumonisin B2, fumonisin B3, ochratoxin A, ochratoxin B, zearalenone, -zearalenol, -zearalenol, -zearalanol, -zearalanol, deoxynivalenol, 3-acetyldeoxynivalenol, T-2 toxin and HT-2 toxin. The recoveries of this method ranged from 72,2 % to 100,0 %. The validated method was used for determination of above-mentioned mycotoxins in 89 beers. Of the total number of beers, 37 were produced in the Czech Republic and 52 in other European countries. Mycotoxins deoxynivalenol, T-2 toxin and HT-2 toxin were found in all beer samples. Common mycotoxins included fumonisin B1, ochratoxin A, -zearalenol and 3-acetyldeoxynivalenol. The mycotoxins aflatoxin B1, aflatoxin B2, aflatoxin G1, fumonisin B2, fumonisin B3, zearalenone and ochratoxin B were identified in less than 50 % of the samples. Mycotoxins aflatoxin G2, -zearalenol, -zearalanol and -zearalanol were not determined in any tested samples. The results of the analysis were subjected to statistical processing where the concentrations determined in Czech and European beers were compared. Principal component analysis and correlation analysis were created for aflatoxin B1, fumonisins, ochratoxin A, -zearalenol, deoxynivalenol, 3-acetlydeoxynivalenol, T-2 toxin and HT-2 toxin. The results of the analysis were compared with published studies.
|
|
| |
|
|
Mini-brewery with Accomodation for Brewer
Paroulková, Michaela ; Šibal, Jan (referee) ; Králová, Zuzana (advisor)
The main aim of my bachelor thesis was to create family brewery with accommodation for brewer at the edge of the small village called Kněžičky. Building contents free parts and has no basment. The main dominant of the brewery is hexagonal tower with gabled roof including boiling room, training room and terrace. Two grand rectangle buildings with partly-walkable roofs follows main tower. In the first building are located spaces for the fermentation of the beer, storaging of required material, puring and subsequently expedition. In the second part is designed simple, but useful accomodation for a brewer. Whole building is designed as a wood frame construction. Design consideration has been conceived so that the single parts and materials co-operates alltogether and effective use of all parts of the building is allowed. Nevertheless the building is non-tradicional construction, it doesn´t bother nature of the village.
|
|
|
Historical brewery - potential for regional development
Mosler, Štěpán ; Boháč, Ivo (referee) ; Králová, Eva (referee) ; Zemánková, Helena (advisor)
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 not many left. It is very difficult to find a new function and especially enlightened investor. 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 thesis attempts to briefly describe and demonstrate the value of brewery architecture which due to dramatic changes in society became endangered. And to offer possible solutions for the preservation this unique buildings their charm and atmosphere for the next generations.
|
|
|
Study some active substances in Czech beer
Pařilová, Kateřina ; Vávrová, Milada (referee) ; Márová, Ivana (advisor)
The aim of this work was to study phenolics and other active compounds in 22 kinds of lager beer and especially to find some differences between Czech beer and beers made in foreign countries. In theoretical part the most useful methods for phenolic and protein analysis are discussed. Further, basic steps of brewery technology are introduced and main beer components with regard to Czech beer specificity are presented. Analysis of total phenolics, total flavonoids, antioxidant activity and most of basic technological characteristics was performed spectrophotometrically. To identification and quantitative analysis of individual phenolics on-line liquid chromatography with photo-diode array (PDA) and mass spectrometry (MS) detection was used. Protein analysis was performed by vertical electrophoresis SDS-PAGE and by Experion microfluidic electrophoresis (BioRad). From the total of 22 samples, 15 Czech beers and 7 beers of foreign marks were enrolled into this study. In these samples levels of brewery characteristics, group antioxidants and individual phenolics were compared. Flask and can beers as well as alcoholic and non-alcoholic beers were compared too. As a model comparative sample the Czech hop of Sládek variety was used. Finally, usefulness of tested parameters to differentiation composition and technology of individual beer samples was evaluated and parameters suitable for Czech beer authenticity analysis were proposed.
|
guest ::
