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Determination of the risk elements and other elements concentration in animal feed
Křehlíková, Jana ; Juglová, Zuzana (referee) ; Diviš, Pavel (advisor)
This thesis deals with the determination of selected microelements and macroelements and risk elements in dog and cat food. The theoretical part describes the nutrition of dogs and cats and focuses on the safety of the food in the context of contamination with risk elements. Another topic discussed is the chemical analysis of feeds, specifically the determination of nutritionally important substances, beneficial elements, and contaminants. The experimental part deals with the preparation and digestion of feed samples and the subsequent analysis of these samples using ICP-OES and AAS methods. The detected concentrations of the elements of interest in the feeds were compared with the feed standards issued by the Department of Veterinary Medicine and the decree issued by the Ministry of Agriculture. The analysed feeds were found to be deficient in some elements. The content of the risk elements in the feed met the legal limits and did not pose a health risk to the animal. Elements for which the legislation does not provide a maximum permissible limit were present in the feed-in in high concentrations that could already harm the animal's health.
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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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Influence of coffee making process on chemical composition of brewed coffee
Trenzová, Kristina ; Divišová, Radka (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with the influence of baristic coffee preparations on the chemical composition of the obtained beverage. Teoretical part of this thesis focuses on coffee growing, processing technology and the chemical composition of coffee beans. In the experimental part were measured samples of espresso coffee, samples prepared by moca pot, flip-drip method, filtrated coffee, samples prepared by french-press technique, vacuum pot samples and boiled coffee. The samples were prepared according to the baristic techniques at first and later with adjusted water and amount of coffee so these methods could be compared with each other. This work focuses on the determination of caffeine and acrylamide content by liquid chromatography, validation of HPLC method, determination of total phenolic content by Folin-Ciocalteu reagent, determination of organic acids by ion chromatography, determination of selected macro and micro elements by inductively coupled plasma in optical emission spectrometry and analysis of aromatic substances using gas chromatography. Based on the processed results and compared methods, it was shown that the moca pot had the greatest influence on the content of caffeine, acrylamide, organic acids and total phenolic substances, and the flip-drip with vacuum pot method had the greatest influence on the content of aromatic substances. From a baristic point of view the highest concentration of caffeine was 3689 mg/l in coffee based on flip-drip method, and concentration of acrylamide was 25,4 mg/l in the coffee based on the same method. The highest value of total phenolic content was determined in moka pot to c = 5,23 g/l. Regarding the mineral representation, the mineral decomposition of coffee beans and espresso were compared, and the highest values were reached by potassium, namely the concentration was 577 mg/l per 1 g of mineralized sample, in the cup of espresso the potassium concentration was 2461 mg/l. The highest content of organic acids was determined in the beverage prepared by moca pot, in terms of selected acids, the largest representation had the succinic acid with the concentration 599,8 mg/l. The highest content of aromatic substances was found in coffee from a moca pot and in coffee by flip-drip method. The biggest part was~made by furfuryl alcohol.
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Monitoring of chemical composition changes in wine during the wine making process
Orságová, Marie ; Punčochářová, Lenka (referee) ; Diviš, Pavel (advisor)
The Chardonnay wine variety was harvested in the region of Znojmo on the wine rout Načeratický kopec. In connection with the entire winemaking process of this particular variety, research was focused on mineral concentration changes during the maturation process. The theoretical part characterizes the technology of wine production, as well as the classification and chemical composition of wine. In the experimental part, the analytical technique of inductively coupled plasma optical emission spectrometry (ICP-OES) was used for the determination of minerals (K, Ca, P, Mg, Na, Zn, Cu, Fe and Mn) in wine. The data show the differences in the concentrations of all macroelements and microelements during the whole wine production technology.
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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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Concentration of selected metals in traditional and herbal teas
Brlíková, Eliška ; Křikala, Jakub (referee) ; Diviš, Pavel (advisor)
This thesis deals with determination of selected metals concentrations in loose green, black and herbal teas purchased in the Czech Republic and beyond. All samples were analyzed by ICP-OES. Most metals were not detected in the extracts. The final metal concentrations that have been detected in the tea extracts meet the legislative limits and do not bring a health risk to humans. The statistical processing of the measured results, based on different concentrations of selected elements, managed to distinguish the extracts from black and green teas.
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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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Mineral and vitamin deficiencies in the elderly and their supplementatin
Nesnidalova, Andrea ; Vágnerová, Tereza (advisor) ; Bárta, Michal (referee)
Seniors often buy inappropriate combinations of dietary supplements based on advertising or peer recommendations, but often to a lesser extent on the recommendation of a professional. It is important for seniors to pay attention to the quality and variety of their diet in order to maintain good health. The bachelor thesis is divided into theoretical and practical parts. In the theoretical part, the first chapter describes the individual vitamins and minerals. The next chapters deal not only with their deficiency and need in the elderly population but also with their correct consumption with regard to further pharmacotherapy. In particular, a chapter dealing with the reasons leading to insufficient food intake in the elderly is described. For the practical part, three main objectives have been set. The research was conducted by questionnaire survey to which a total of 67 respondents aged 65-90 years answered. The first objective was to find out what dietary habits seniors have in their home environment and what vitamins and minerals they are deficient in. A sub-objective of this question was to determine whether current supplementation is justified in this population given the results of the questionnaire survey. The second objective builds on dietary diversity and explores the principles of good...
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Využití hořčíku u nosnic
Jandová, Eliška
This thesis deals with determination of the magnesium and iron retention in organism. In experiment there were used laying hen of carrier type of hybrids Bovans Brown from the age of fourteen months. Chicken were fed ad libitum with feed mixture with the indicator of chromium oxide the entire duration of the whole experiment. From the beginning of the clutch eggs were removed to specify the strenght of eggshells. The balance digestibility of magnesium was found out in three-day periods. Feed consumption was found out by indi-cator method. An average balance digestibility of magnesium in feed mixture was 55, 1 %. Maximum, about 58%, was reached between 40 – 60 days after laying of the first egg. The course of retention of magnesium from 43rd day before laying of the first egg to 73rd day after laying of the first egg is possible to express by polynomial second degree equation Y= -0,0009x2 + 0,1316x + 54,12; R2 = 0,6414. Daily retention of magnesium that was 127 mg before beginning of the clutch was increased with proceeding clutch and egg weight. During the clutch there were retained 179 – 196 mg of magnesium in the layer´s body. Average content of magnesium in eggshells was 3,771 ± 0,2131 g/kg. For the whole reten-tion period average feed consumption was 120,13 g. In evaluation of quality of eggs from the age of 17. to 29. weeks all values were identical with a technological manual of given hybrid.
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Luštěniny jako zdroj vybraných makro a mikronutrientů
Bernreiterová, Hana
This diploma thesis deals with the determination of amount of selected mineral elements (Ca, Mg, Fe, Zn and Cu) for eight species of pulses: Cicer arietinum L., Glycine max L., Lens culinaris Medic., Phaseolus vulgaris L., Pisum sativum L., Vigna angularis L., Vigna radiata L. a Vigna unguiculata L. The differences between species in the amount of selected mineral elements and the dependance of the amount on the method and location of growing were determined by atomic absorbtion spectroscopy. The results determined that the best source of selected mineral elements is soybean. On contrary the least useful source is pea. Consummation of common bean and Vigna species is beneficial because of high amount of calcium and magnesium. Except soybean the high amount of ferrum, zinc and copper is in lentil. There was no general difference in amount of selected mineral elements based on location and method of growing.
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