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The study of various methods of preparation of the milk sample for milk analysis by ICP-OES technique
Kaňová, Veronika ; Vítová, Eva (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 and Mg). Milk is a really complicated polydisperse system, that’s the reason why the preparation of samples with milk is very important step before the measurement itself. In addition to accuracy choosing the sample adjustment method, other factors such as time, work intensity, or cost need to be considered when. In the thesis a comparison of four selected methods of sample preparation was made: direct analyse of milk, dilution with addition of Triton X-100, wet microwave ashing and destruction of matrix with TMAH (tetramethylammonium hydroxide). Selected elements were analysed with the help of ICP-OES. This diploma thesis builds on the bachelor thesis, which deals with the same problem. Final concentrations were compared with certified values of skimmed powdered milk. Data showed that the most accurate are methods of preparation of wet microwave ashing and destruction of matrix with TMAH. By using these methods, the effect of the dairy matrix that caused problems in the analysis, was largely eliminated. The diluted samples with and without Triton X-100 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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Basic characterization of selected samples of animal feeds
Svoboda, Ilona ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
The aim of the diploma thesis was to choose poper parameters for a quick and simple characterization of animal feed, to verify working procedures and to apply these on chosen samples. Within the scope of this work, samples of animal dog feed produced in a private company „Adamkovy tlacenky“ were analyzed. The feed is in the form of brawn, stored in artificial casing; it consists of up to 80% of animal components and up to 20% of vegetable components, while the rest of the weight is the pork gelatine. The feed does not contain preservatives, colourings as well as any other chemically produced additives. For the analysis three formulas were chosen: "Hovězinka", "Kuřátko" and "Srdcovka", the composition of which is protected by the patent. The choice was made to include samples of different composition. The content of raw crude protein, fat, fibre, dry basis, and ash was determined. The obtained values were compared with the standards for feed normally utilized by the feed industry. The results will be used to improve the formulas and to develop new types of feed.
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Determination of selected metals in fruit squashs
Drobilová, Marcela ; Vránová, Dana (referee) ; Diviš, Pavel (advisor)
The theoretical part of the thesis deals with the technology of fruit juices production and characteristics of the known varieties of elderberry. There are also summarized available information on the presence and properties of minerals in food. In the practical part of the thesis 17 different varieties of elderberry juice and commercially available juice sold as food supplements were analyzed using ICP-MS technique. The concentrations of 15 selected essential and toxic elements were determined in these juices.
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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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Comparison of individual species and groups of fruit in terms of content and properties of nutritionally valuable components
HAVLÍKOVÁ, Martina
The work deals with the content and features of nutritionally valuable fruits constituents and detects the frequency of its consumption among secondary school students. The theoretical part deals with the basic breakdown of fruit with a description of important species of each group. There are also distributed and described, given the importance in human nutrition, most nutritionally valuable components of fruits - vitamins, antioxidants, minerals, roughage, carbohydrates, proteins and lipids. The practical part deals with the comparison of individual fruits in terms of nutritionally valuable constituents. When comparing nutritionally valuable constituents of fruits was found that nuts exhibits considerably higher amounts of vitamins, minerals and lipids than other group of fruit. This section also contains a survey related to questions about the frequency and popularity of eating fruit in secondary school students aged 17-20 years. The results are analyzed and graphically displayed. Research shows that 98 % of students likes fruit and prefer to eat it fresh. Their favorite kind are apples, which are our most usual fruit. In contrast, the fruits that students do not like to include grapefruit and currant. According to the survey, students understand the importance of fruit in the diet to their health, but it is important to pay attention constantly to have a varied diet in adolescents.
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Antioxidants in food and possibilities of nutrition application
DUBNOVÁ, Martina
The bachelor thesis concerns with the occurrence of antioxidants in foods, the possibilities of their applications in nutrition and population awareness on the topic antioxidants. The theoretical part describes the types of antioxidants, effects on human health and occurrence in foods and their recommended daily dosage. Further characterize free radicals and their negative effects on the organism. The practical part contains the research of the knowledge about antioxidants in the population in the form of a questionnaire. The results are analyzed and charted. The antioxidants are known by 82% of respondents. For the question ?What the antioxidants are used for? answered 54% of respondents correctly. In which foods the antioxidants are is known by 58% of respondents. The greatest awareness of antioxidants is in the group of workers, as well as students and in the group of retired respondents is the awareness of antioxidants slightest. Research shows that awareness of antioxidants which play a major role today in the prevention and treatment of lifestyle diseases and shows that more than half of respondent?s answers were inadequate.
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Eating habits of Secondary School Pupils in Prague
JÍROVÁ, Lucie
A brief outline of youth nourishment, important nutrients, vitamins and minerale. The text is divided in a way so that the reader can get a clearly organized view on youth nourishment and its recommended amounts. The purpose of this project is to give its readers a current recommendation regarding nourishment, and also to gather all modern scientific information about food and healthy nourishment so that it can be used easily in common life. The main part of the thesis concentrates on a research of the nutrition habits of the youth including its final evaluation. In conclusion the thesis compares pieces of nutrition knowledge with the research results.
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Pregnant and nursing woman´s general model of diet.
VRÁBKOVÁ, Petra
The principal aim of this bachelor thesis was at first analysis of literature concerning the subject of pregnant and nursing woman. The opinion poll with 27 questions followed after that. It should validate or overcome three theories. The first one was related to the presumption, that the supplements of food and the better way of feeding during the pregnancy influence the tiredness of the pregnant woman and also the proper process of the pregnancy. This theory stayed unconfirmed. The second hypothesis is looking for an answer to the question, if the length of breast feeding was influenced by the nursing mother´s right way of living. The second theory was not confirmed by the partial questions. The third hypothesis was dealing with food supplements used during breast feeding and their influence on the quality of hair, nails, teeth and skin. In this case there was found some context.
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Determination of minerals in slates by infrared spectroscopy and chemometrical methods
Ritz, M. ; Vaculíková, Lenka ; Plevová, Eva
Application of infrared spectroscopy with chemometry methods to determination of chlorite, muscovite, albite and quartz in slates was suggested. Eighty six samples of slates from different localities in Czech Republic were used in this study. X-ray diffraction with Rietveld method was used as primary reference method. Infrared spectra were collected by the bromide pellets technique and by the diffuse reflectance technique. The infrared spectra and the results of X-ray diffraction were used for creation of the chemometry models by Partial Least Squares regression. The equality of results of chemometric models and results of X-ray analysis were tested. The statistical tests certified the statistical equality of results.
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Tha influence of iceberg melting on economic situation of Greenland
Chuchlíková, Zuzana ; Ryvolová, Ivana (advisor) ; Petrášek, František (referee)
The aim of this piece is to estimate the future progress of the economic situation of Greenland on the basis of available dates. To show whether the initiation of mining enables to separate Greenland from Denmark, which Greenland has urged for a long time to and which has not been available because of financial reasons. Thanks to comparison to progress of Norway, which depended very much on fishing before oil extraction (as well as Greenland today) we can see the importance of mining in Greenland. Besides mining, iceberg melting has a great influence on accessibility of this island (new naval routes etc.). The point of this piece is to show that climate changes and iceberg melting are not so negative and a threat for all areas of the world. It could also mean important economic assets for particular areas.
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