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The basic chemical parameters of berries from some gooseberry cultivars
Nguyen, Quynh Anh ; Vespalcová, Milena (referee) ; Hrstka, Miroslav (advisor)
This bachelor thesis deals with assessment of basic chemical parameters in berries of some gooseberry cultivars. In theoretical part the taxanomy classification of gooseberry and its botanical characteristics are mentioned. The history of breeding, appropriate conditions, including the most common diseases and pomology of each cultivars are also described. Next chapter is dedicated to the chemical composition of gooseberry. In experimental part some chosen chemical parameters (yield of juice, soluble dry matter content, dry matter general content, pH, titratable acidity, formol number and reducing saccharides content) of few gooseberry cultivars were determined.
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The influence of the autochthonous yeasts and technological process on the chemical parameters the wine
Chmelová, Petra ; Hrstka, Miroslav (referee) ; Vránová, Dana (advisor)
This bachelor´s thesis deals with influence of the autochthonous yeasts and technological process on the chemical parameters of the wine. The theoretical part describes the history of viticulture in the world and in Bohemia and Moravia, characteristics of grapevine, morphological structure and chemical structure of grapes. There are also analyzed the individual proces steps in the production of wine and consequently the most commonly used of analytical methods for the examination of the must samples. The experimental section presents the results obtained by monitoring chemical changes in the examined musts during fermentation. Experimentally measured parameters in this work are reducing sugars, pH, titratable acids and ethanol content in the samples must. The samples used for analysis were from variety of the Grüner Veltliner from village Kobylí.
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The significance of magnesium for human health
Škeřík, Jan ; Hrstka, Miroslav (referee) ; Vránová, Dana (advisor)
Aim of this bachelor thesis was to compare different forms of magnesium. The characteristics and history of magnesium was briefly described at the beginning of the theoretical part. The following chapters explain the importance of magnesium in the body, hypomagnesemia, hypermagnesemia. Another section describes magnesium effect on various diseases, increased intake of magnesium and magnesium metabolism. The ninth and tenth chapter describes the effects of nicotine and alcohol on the metabolism of magnesium and magnesium content in drinking and mineral water. Conclusion of the theoretical part is dedicated to the description of the analytical methods of dosage forms. At the heart of the practical part was using several commonly used methods to determine best magnesium addition. It was the method of determination of the mass uniformity, determining magnesium contents in the tablet, the determination of disintegration, dissolution determination and hardness determination.
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Determination of tin in canned fruits
Šťávová, Elena ; Hrstka, Miroslav (referee) ; Diviš, Pavel (advisor)
This bachelor’s thesis deals with determination of tin in canned fruits. Fruit processing, manufactory of compotes, manufactory of metal packaging products, corrosion of cans, chemical behaviour of tin in food, its potential toxicity, possibilities for the determination of tin in food and characterization of inductively coupled plasma optical emission spectrometry are described in theoretical part. In experimental part, ICP-OES technique was firstly optimized and then 28 different compotes purchased at common stores were analysed. The concentration of tin was determined only in fruit juice due to the easier sample preparation, even though quantity of tin in the solid part and in the juice can differ. However, the difference is not too big. Measured concentrations of tin were compared with the maximum permissible level of tin in canned food determined by European legislation. None of them exceed the 200 mg/kg level. When processing the results, it was found that the coating of the can has a significant influence on the content of tin in canned fruits. Concentrations of tin in laquered cans were significantly lower than in unlaquered cans.
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Analysis of milk by ICP-OES technique
Kaňová, Veronika ; Hrstka, Miroslav (referee) ; Diviš, Pavel (advisor)
The theoretical part of the thesis deals with the chemical composition of cow’s milk, with the description of chosen methods of sample pretreatment and with the description of the used technique ICP-OES. The practical part is aimed at individual preparations of samples and at analysis of chosen chemical elements (Ca, Na, K, Mg a P). Milk is a really complicated polydisperse system. The preparation of samples with milk is very important step before the measurement itself. In the thesis a comparison of four selected methods of sample preparation was made: bare dilution, dilution with addition of Triton X 100, wet ashing and sonication. Selected elements were analysed with the help of ICP-OES. Final concentrations were compared with CRM of dried milk. Data showed that the most accurate are methods of preparation of diluted sample and wet ashing. Four different types of milk were analysed with the help of those two selected methods. The diluted samples showed a bigger anomaly of measuring than the mineralization of wet ashing which came to the loss of analyte because of fat elements contained in milk.
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The changes of Rubisco amount in Norway spruce grown at gradient of altitudes
Tomasz, Teresa ; Vítová, Eva (referee) ; Hrstka, Miroslav (advisor)
The study deals with differences of Rubisco enzyme content in Norway spruce needles (Picea abies L.) growing at different altitudes, thus at different concentrations of carbon dioxide. The collection of samples was performed in Jeseníky by Global Change Research Centre, Academy of Sciences of the Czech Republic. The samples of exposed and shaded needles were collected from 39 spruce trees in three altitudes – low (L), medium (M) and high (H). To separate Rubisco enzyme, the SDS-PAGE method was used, the content od Rubisco was determined by computer densitometry. The results of exposed needles confirmed that Rubisco content decreases with increasing altitude, however, in the case of shaded needles, there was no proof of a significant influence of altitudes on Rubisco enzyme amount. At low altitude, Rubisco content was significantly higher in exposed needles in comparison with shaded needles. At medium and high altitude no significant difference was detected between exposed and shaded needles.
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Assembled Steel Tanks
Konečný, Jiří ; Hrstka, Miroslav (referee) ; Marcián, Petr (advisor)
This thesis deals with the area of bolted steel tanks, which constitute a significant share of the total number of tanks of all types of tanks. In the first part of this thesis is mentioned short history of bolted steel tanks, tanks producers and major standards and standards governing the calculation and realization not only these tanks. In the next part of this thesis mentions the various segments and major parts of bolted steel tanks. This is followed by a short description of the assembling. The last section describes the creation of a computer model of roofs used in simulation program ANSYS and subsequently performed stress-strain analysis for snow loads according to various snow areas for different FEM model in the 2D and 3D levels.
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Energy drinks in contemporary nutrition
Krňávková, Martina ; Hrstka, Miroslav (referee) ; Vránová, Dana (advisor)
Bachelor's thesis is dealing with consumption of energy drinks and their effects on the human organism. The introductory part gives an overview of the most frequently occurring components of energy drinks including their chemical composition, properties and sources of these substances and nutrition recommendations. The next section describes the effects of consumption of energy drinks on the human body and health in general. The final part deals in detail with the impact of their consumption on sports performance and on human health and the possible consequences of consuming energy drinks combined with alcohol.
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Spectrophotometric determination of ascorbic acid in coloured samples
Moravcová, Gabriela ; Vespalcová, Milena (referee) ; Hrstka, Miroslav (advisor)
This bachelor’s thesis deals with spectrophotometric determination of ascorbic acid after the xylen extraction in coloured samples. The theoretical part deals with reactions, biochemistry and occurrence of ascorbic acid in foodstuffs. Also, it is dealt with various methods of determination of ascorbic acid, such as HPLC methods, electrochemical methods, titrimetric determinations, spectrophotometric determinations or polarographic method. In the experimental part of this method were first determined the concentration of ascorbic acid in the standards, then in real samples (vitamin tablets, orange juice and the juice of cultivated varieties of elderberry). Some validation parameters of the method were also determined. Sensitivity of the method was determined to 1,6772, linearity to 0,9990, limit of detection was set at 0,0466 mg/ml and the detection limit at 0,1552 mg/ml. Accuracy of the method was expressed as relative standard deviation, which gained 3,00% in value.
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Impact of elevated carbon dioxide concentration on Rubisco content in Fagus sylvatica and Picea abies
Hamříková, Dominika ; Vítová, Eva (referee) ; Hrstka, Miroslav (advisor)
In this bachelor’s thesis content of Rubisco in beech (Fagus sylvatica) and Norway spruce (Picea abies) was studied. The plants were cultivated in conditions with ambient carbon dioxide concentration (350 mol·mol-1) and elevated carbon dioxide concentration (700 mol·mol-1). The content of Rubisco in exposed and shaded leaves or needles was compared. The content of Rubisco was determined by SDS-PAGE method. A significant decrease in Rubisco content was demonstrated in conditions E versus A in shaded beech leaves. In other cases, the decrease was not so significant. A comparison of exposed and shaded needles also did not show a statistically significant difference, but in shaded beech leaves against exposed leaves Rubisco content was significantly lower, especially in conditions E.
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