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Evaluation of the influence of the pasterization and filtration on selected chemical components of beer
Vopelková, Dominika ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
The aim of this work was to study the influence of the pasteurization and filtration on selected chemical compounds in beer. Specifically, the influence on elemental composition, content of organic acids, carbohydrates and phenolic substances was studied. Optical emission spectrometry with inductively coupled plasma (ICP-OES) was used for elemental analysis of beer. Analysis of organic acids was evaluated by Ion chromatography. For analysis of carbohydrates was used High performance liquid chromatography with ELSD detector (HPLC-ELSD), phenolic compounds was evaluated by HPLC with diode array detector (HPLC-DAD). Data from analysis of beer was performed by usage of statistical methods (analysis of variance and principal component analysis). Parameters that showed the most significant differences between individual groups of beers were obtained. Correlations between the variables and the technological beer processing operations were found. 12 parameters of total 23 were affected. The effect of filtration and pasteurization was observed in content of the iron, silicon, potassium and magnesium, malate, monosaccharides glucose and fructose and phenolic compounds.
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Heat treatment of milk and its importance
VOČADLOVÁ, Kateřina
The aim of this work is to assess the public knowledge of heat treatment, its purpose and effect on milk quality and to find out their attitude to raw milk consumption. Heat treatment of milk is a commonly used part of dairy processing. Although the heat treatment has a significant impact on ensuring microbial quality, safety and shelf life of milk, its application still face a public disagreement, primary in connection with potential health benefits, which are lost during heat treatment. The survey took place (from November 2015 to February 2016) in a randomly selected group of respondents (n=265). It was found that 22 % of respondents buy raw (unpasteurized) milk and only 27 % of them reported pasteurizing of the milk before consumption. 68 % of respondents just cool the milk down and consume it without any thermal treatment. 23 % of respondents though that pasteurization has negative effects on milk quality and 21 % of respondents said that consumption of milk pose no health risk.
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Sludge pretreatment and its further utilization
Němec, Jan ; Dlabaja, Tomáš (referee) ; Elsässer, Thomas (advisor)
The thesis deals with methods of pre-treatment (disintegration) of sewage sludge, which offers an opportunity for better operation of a waste water treatment plant. The introduction is aimed at sewage water and sludge dividing, and then at their characteristics. In this thesis a current state of sludge disposal within the reference to the legislature and how to divide the methods of disintegration is also marked. Afterwards a description of selected methods of sludge disintegration, their comparison and the applicability of thermal disintegration to pasteurization of sewage sludge is included.
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Risks of salmonellosis and prvention of this disease in public health education
VAČKÁŘ, David
This bachelor thesis deals with the origin and development of salmonellosis and the risks related to the bacterial disease. Symptoms of the disease as well as the varied ways the infection spreads are described. Risks associated to storing, processing, and taking in food are pointed out. These are related to prevention of the disease and its treatment when it develops, focused on fluid and food intake, too. The thesis includes a questionnaire survey about this diarrheal disease, with a concluding processing and evaluation of the questionnaires.
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Milk quality from vending machines
JEŘÁBEK, Tomáš
The aim of this work was to assess the quality of milk from vending machines. The quality and microbiological characteristics of raw cow´s milk from two farms were assessed; one from the South Bohemia Region and one from the Pilsen Region.
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The Application of the HACCP System in the Company "MADETA a. s."
KAZILOVÁ, Lucie
The aim of this work was to go thoroughly throw the already existing HACCP system in the company and to evaluate if the hazard is treated in a good way and to find other more effective approach to prevent the hazard. An effort was focused on the primary processing milk and on the process of the treatment of acidified milk products. While investigating current condition the author has made several experiments focusing on the settled conditions of important process in the production (for ex. pasteurization). Chemical, physical, qualitative and microbial properties were observed on a concrete diary product. The main investigation {--} the simulation of disturbance of the cooling chain - was performed where products were exposed to various temperatures for various time periods. During this test were observed: the temperature, pH and microbial changes in exposed products. Due to results form all observations that where performed in this research its possible to proclaim that the HACCP system is settled in a good way and even if above mentioned situation happen the product is safe.
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