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Study of the Selected Types of Sulphur Compounds in Beer and Brewing Materials
Mikulíková, Renata ; Ventura, Karel (referee) ; Ventura, Karel (referee) ; Čáslavský, Josef (referee) ; Márová, Ivana (advisor)
Much attention has been recently devoted to sensorially active substances affecting beer quality in the Czech Republic and worldwide. Among them, the heterocyclic and sulphur containing compounds play an important role, some of them with high sensorial activity even in extremely low concentrations. Trace amounts of these compounds, which can be frequently found in foods, participate in formation of their aroma and this effect can be generally evaluated as favorable However, in malt or beer it is true only to a limited extent and the presence of heterocyclic and sulphur containing compounds are in this respect assessed rather unfavorably. The aim of the present study was to provide a survey about of problems in the field of sulphur containing compounds in barley, malt and beer, to describe metabolic paths leading to their formation and to verify experimentally possibilities of their determination using modern analytical methods. Sulphur-containing amino acids are a natural part of barley, malt and beer and are precursors of the origin of volatile sulphur substances. The most frequently occurring sulphur amino acids, metionine, cysteine and homocysteine, were selected for analytical monitoring. The method of gas chromatography was used to determine sulphur-containing amino acids in barley, malt and beer. Prior to the analysis, sulphur-containing amino acids were derived and volatile N(O,S)-ethoxycarbonyl propyl esters were formed; they were subsequently analyzed using the gas chromatography with mass detector (GC/ MSD) and the gas chromatography with flame photo detector (GC/ FPD). Direct analysis of sulphur volatile substances is possible only rarely as they are found in the analyzed matrices (malt, beer) only in very low concentrations ( g/kg,l - ng/kg,l). Before the analysis, the analytes must be extracted from the matrix and concentrated. The modern analytical methods SPME (Solid Phase Micro Extraction), SPDE (Solid Phase Dynamic Extraction) and TDAS (Thermal Desorption Autosampler) were experimentally compared for the extraction and subsequent concentration of sulphur volatile substances. The method of gas chromatography with flame photo detector was used to determine sulphur volatile substances. Following volatile sulphur substances were monitored: dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide, carbon disulphide, ethyl sulphide, diethyl disulphide, methionol, 3-methylthiophen, ethyl thioacetate, 2-methyl-1-buthanthiol. Only metionine was detected in significant amounts in the barley samples analyzed. Not only content but also dependence on a variety and locality were studied. Further, changes in methionine, cysteine and PDMS content during malting were followed. Results proved a significant decline in these substances content depending on the kilning temperature. Three types of fibers were tested for the analyses of the selected volatile sulphur substances in beer in the SPME method. PEG - a fiber with stationary phase Carbowax, PDMS - a fiber with stationary phase polydimethylsiloxan and a combined fiber CAR/PDMS - Carboxen and polydimethylsiloxan. Carbon disulphide, methionol, dimethyl sulphide, 3-methylthiophen and diethyl disulphide were detected with this method. Content of the other analyzed volatile sulphur substances was below the limit of detection. Further was tested usage the SPDE and TDAS methods. Both methods appear to be the suitable for the determination of volatile sulphur substances in beer.
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Determination of total protein, carbohydrates and polyphenols in beer
Dostálová, Blanka ; Gregor,, Tomáš (referee) ; Diviš, Pavel (advisor)
This master‘s thesis deals with the analysis of 65 different beers, with a focus on finding differences between Czech tap ales, lagers Czech, Czech special beers and foreign beers. Czech beers were compared by the results of analysis among beers bearing the indication "Czech beer" and the group without this indication. The total amount of proteins, polyphenols and carbohydrates was determined using UV-VIS spectrometry. The history of brewing, the nature and types of Czech beers and protected geographical indication "Czech beer" were described. Raw materials for beer production and brewing technology have been listed and described. In the last part of the research, components of beer and the principle of the UV-VIS spectrometry have been specified. Th determination of total protein was performed using Hartree-Lowry method, which is based on two-component reagent. The first component is the biuret agent, the second component is the Folin-Ciocalteau reagent for phenols. Determination of the polyphenols has been carried out by the Folin-Ciocalteau reagent and total carbohydrates were determined spectrophotometrically according to the Analytica EBC using anthron agent. The results were statistically processed and evaluated in the final part.
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Determination of organic acids in beer
Štáblová, Taťána ; Divišová, Radka (referee) ; Diviš, Pavel (advisor)
The topic of this bachelor’s thesis is determination of organic acids in Czech beers with protected geographical indication. There are described the main components for beer production and the production of malt and beer itself in the theoretical part. Part of this work is dedicated to analytical methods used in determination of organic acids. High–performance liquid chromatography and ion chromatography were used to determine the content of organic acids. The experimental part deals with sample preparation, calibration solutions and procedure of analysis. The obtained results of analyzed substances are summarized, discussed, and compared with results of analyses of foreign papers. Differences in content of organic acids in lager and draught beers were determined. Five lager beers and five draught beers were used for the analysis.
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Welding of stainless steels in food industry
Staněk, Vít ; Hála, Michal (referee) ; Kubíček, Jaroslav (advisor)
The work, created in the bachelor degree, is engaged in welding technology food containers, namely CTK. There are some technologies with their advantages, disadvantages and specifications for welding stainless steels. The selected CTK is given manufacturing process, in the experiment were created welds, which are evaluated and WPS.
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Energy usage of beer production
Maťa, Jakub ; Tuhovčák, Ján (referee) ; Hejčík, Jiří (advisor)
The bachelor thesis deals with the issue of energy consumption of beer production. The first part focuses on the technology of beer production itself, the understanding of which is a key prerequisite for assessing the possibility of using a heat pump for this process. The main part then describes the individual processes and their energy consumption. Finally, it evaluates the use of a heat pump and shows if it could reduce the energy requirements of beer production.
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Brewing industry
Artýszková, Jana ; Illková, Kateřina (referee) ; Omelková, Jiřina (advisor)
The aim of the theoretical part of the thesis is the study and the treatment of the problem of the manufacturing of beer, focused on the czech conditions and classical Czech technology. Within the theoretical part the history of this branch of industry together with the modern methods, enabling greater productivity of beer production, are summarized. Experimental part of the thesis was carried out in a small brewery in Czech republic, producing aproximately 10 000 hl per year. In this brewery the selected parameters were studied not only in the course of cooking and fermentation of beer, but during the output control in racking to the drums and plastic bottles, as well. The studied parameters were as follows: the sugar content of front and wort, the control of microbiological contamination in fermenting cellar and in beer-storage cellar, the content of CO2 by last stage of fermentation and pH- value and color by the end-product.
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Monitoring of the occurrence of mycotoxins in beers from market retail
Wawroszová, Simona ; Pospíchalová, Markéta (referee) ; Běláková, Sylvie (advisor)
This master thesis deals with monitoring of a content of deoxynivalenol, its metabolite deoxynivalenol-3-b-D-glucopyranoside and ochratoxin A in beer samples collected from retail market in the Czech Republic, Poland and Slovakia. The theoretical part describes general characteristics of mycotoxins, its transfer from field barely through malt to beer and its occurrence in beers. Malting process and brewing technology were also mentioned. Subsequently possibilities for a determination of the mycotoxins by the chromatografic and immunochemical method were presented. The experimental section describes analysis of 30 samples of beer. The analyses were conducted using ultra high-performance liquid chromatography with fluorimetric detection (UPLC/FLR) for ochratoxin A and high-performance liquid chromatography coupled with mass spectrometer (HPLC/MS) for deoxynivalenol and its metabolite. Ochratoxin A was detected in 25 of the 30 samples in concentration range of 0,6 - 82,5 ng·l-1. Deoxynivalenol was found in 24 of the 30 samples with concentration range of 2,29 - 12,57 ug·l-1 and deoxynivalenol-3-b-D-glucopyranoside was occure in 19 of the 30 samples in concentration range of 2,45 - 12,47 ug·l-1. It was also assessed the relationship between beer gushing and presence of mycotoxins in beer. No connection between the parameters has been found. Consequently it is not possible to predict beer gushing from the presence of mycotoxins.
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Microbrewery automation
Širůček, Pavel ; Matyáš, Pavel (referee) ; Marada, Tomáš (advisor)
Thesis discusses the basics of brewing technology, ingredients needed for beer production, homemade microbreweries, basic procedures and principles used in those breweries and their application. It also discusses the specific solution of selected microbrewery, its design, assembly and automation, including a description of the control software. Selected microbrewery consists of three containers, uses gas burner for heating and transfer pump for pumping. Programmable automatic PLC LOGO! program serves as a control unit of the microbrewery.
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Health effects of Czech beer
Bokrová, Jitka ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
The aim of this bachelor thesis was to study physiological effect of various kinds of lager beer and to compare these effects in Czech beer and several beers produced in foreign countries. In theoretical part Czech beer characteristics and biologically active compounds in beer are described. Quantification of total phenolics, total flavonoids, antioxidant activity and bitter substances was performed photometrically. The quantity of vitamin C was determined by high performance liquid chromatography with spectrophotometrical detection. Beer buffering capacity was analyzed by pH measurement in artificial stomach and intestinal liquid, respectively. Analysis of physiological effect was accomplished by analysis of proteolytic enzyme activity. The total of 22 samples (16 Czech and 6 foreign lager beers) was studied. In these samples levels of basic technological characteristics and buffering capacity were compared. Alcoholic and non-alcoholic beers were compared too. According to experimental data it was confirmed that consumption of Czech beer (mainly lager beer) positively influences digestion process and activity of digestive proteolytic enzymes.
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Minibrewery in Vyškov
Zvolský, Dalibor ; Rozehnal, Miroslav (referee) ; Štěpánek, Ladislav (advisor)
The master’s Thesis – Minibrewery in Vyškov, has a form of project documentation which contains relevant requirements according to valid regulations. The proposed building is situated on the plot number 2123/72 in the city Vyškov. It is a detached building which stands separately on the flat terrain. It is a two-storey building with partial basement. It is formed from three units – a minibrewery, a brasserie with kitchen and an administrative part. It is made of monolithic reinforced concrete frame, brick blocks with vegetative flat roof. The upper level attic gable is at the height of 8,880 meters. The seminar paper – minibrewery in Vyškov – is a part of the Master’s Thesis.
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