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Characterization of plant-based component of selected foodstuffs using techniques of molecular biology and instrumental methods
Tomíšek, Martin ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The aim of this work was to compare authenticity analysis in selected food products with fruit component by using, instrumental and molekular methods. Particularly, the presence of blueberries in fruit–based foodstuffs was verified. The theoretical part is focused on the characterization, chemical composition and botanical classification of blueberries (European blueberry and Canadian blueberry). It also contains an overview of instrumental and molecular diagnostic methods that can be used for the analysis of these fruits. The experimental part focuses on the selection of a suitable method of DNA isolation, and primers for the detection of blueberries in commercial products. DNA analysis was performed by qPCR and HRM analysis. In the experimental part, DNA was isolated in sufficient quality for PCR and the presence of blueberries in foodstuffs was verified by qPCR. Using HRM analysis, we were able to differentiate between bilberry (Vaccinium myrtillus) and blueberry (Vaccinium corymbosum) in control samples and in some commercial products. Certain phenolic acids and some flavonoids specific for blueberries were detected by HPLC. The total content of polyphenols and flavonoids was determined by UV / VIS spectrophotometry.
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Determination of pKa of humic acids by means of UV/VIS spectrometry
Kratochvílová, Romana ; Maršálek,, Roman (referee) ; Klučáková, Martina (advisor)
The behaviour of humic acids in aqueous solutions is closely connected to the content of acid functional groups and their dissociation abilities. The titration methods are the most often used for the research of acid-base characteristics of humic acids, their results should lead to the determination of the content of functional groups and their pKa. However the determined values depend on many factors including the titration speed. The spectrophotometric determination of dissociation constant was used in this diploma thesis. Reliability of this method was confirmed in bachelor thesis where is mentioned that spectrophotometric determination of pKa corresponds with realistic dissociation behaviour of humic acids in the water much more better than values obtained from titration methods. The principle of newly used spectrophotometry method is the preparation of humic acids solutions in three different media with different pH values. Acid groups of humic acids are practically completely dissociated in intensely basic environment and the measured absorbance is caused by anion of „humate“. On the contrary their dissociation in acid environment is suppressed so much that we measure the absorbance of non-dissociated molecules of humic acids. Deionized water was used like neutral solvent. Water was replaced by acetic buffer in this thesis because of water’s properties which have significant influence on solutions' pH. Buffer was used for diluting or for solubilisation and in these both cases more stable pH values were occurred. The aim of this diploma thesis is investigate UV/VIS spectra of various solutions of humic acids with different values of pH and determinate mean value of pKa of humic acids which could be used like comparison of dissociation behaviours for vary samples. Values of acid dissociation constant were determined from measured dates and compared with values obtained by titration method. The UV/VIS spectra gained in combination with the results of pH measuring and the conductivity next showed the differences in the behaviour of differently prepared samples of humic acids.
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Bioceramic materials bioactivity testing via simulated body fluid
Holbusová, Eva ; Novotná, Lenka (referee) ; Salamon, David (advisor)
These days, there is a possibility of joint replacement implantation, more common dental implants, or regeneration of bone fractures using bone graft replacements is more accessible than in history. Bioceramic materials are used for these purposes. Bioceramics is a non-toxic ceramic material. It is characterized by its bioactivity and biocompatibility. Bioactivity testing of bioceramics is performed using simulated body fluid (SBF). In addition, the change in the concentration of calcium ions was investigated during the testing. The aim of the work was to determine whether the concentration of calcium ions changes between bioceramics and SBF. Bioceramic samples were prepared by two methods, namely freeze-casting and cold isostatic pressing. What was soaked in c-SBF was prepared according to Kokubo. The analysis of SBF was performed using a colorimetric method with a reagent of Murexide solution and reagent KIT. The concentration of calcium ions in the SBF after soaking samples in a testing cycle 0, 3, 7, 14, and 21 days was measured using a UV/VIS spectrophotometer. In addition, X-ray diffractometry was used to determine the phase composition of the material before soaking in SBF. The change in calcium ion concentration during the test cycle in the bioceramic – SBF system was confirmed with UV/VIS spectrophotometry. The most significant increase in concentration was recorded on the third day of soaking. The assumption of an apatite layer formation on the soaked bioceramic samples was supported by a change in the concentration of calcium ions SBF and the change in weight of the material after soaking. It was found that using indirect colorimetric determination delivered better results when the Murexide indicator was used instead of KIT.
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Analysis of juices of selected red and white currant varieties
Černá, Anna ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
Presented diploma thesis deals with the analysis of juices of selected red and white currant varieties. The theoretical part is dedicated to the characteristics of a currant, biologically active substances of its fruits, its growing proces and the utilization of currants in the food industry. The analyzed parameters of currants - phenolics, anthocyanins and vitamin C are also characterized in the theoretical part with possibůe methods of their determination. The experimental part is devoted to the preparation of samples and the working practices of individual analysis. Six selected varieties of white and eleven varieties of red currant from Research and Breeding Institute of Pomology Holovousy Ltd. and six varieties of white and ten varieties of red currant from private grower were used for the analysis. Total phenolics and anthocyanins were determined spectrophotometrically, the content of vitamin C was determined by HPLC. Higher values of these compounds were measured mainly in the varieties of Research and Breeding Institute of Pomology Holovousy Ltd. Varieties of red currants contained higher amounts of total phenolics and anthocyanins while white currants contained higher amounts of vitamin C.
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Bioceramic materials bioactivity testing via simulated body fluid
Holbusová, Eva ; Novotná, Lenka (referee) ; Salamon, David (advisor)
These days, there is a possibility of joint replacement implantation, more common dental implants, or regeneration of bone fractures using bone graft replacements is more accessible than in history. Bioceramic materials are used for these purposes. Bioceramics is a non-toxic ceramic material. It is characterized by its bioactivity and biocompatibility. Bioactivity testing of bioceramics is performed using simulated body fluid (SBF). In addition, the change in the concentration of calcium ions was investigated during the testing. The aim of the work was to determine whether the concentration of calcium ions changes between bioceramics and SBF. Bioceramic samples were prepared by two methods, namely freeze-casting and cold isostatic pressing. What was soaked in c-SBF was prepared according to Kokubo. The analysis of SBF was performed using a colorimetric method with a reagent of Murexide solution and reagent KIT. The concentration of calcium ions in the SBF after soaking samples in a testing cycle 0, 3, 7, 14, and 21 days was measured using a UV/VIS spectrophotometer. In addition, X-ray diffractometry was used to determine the phase composition of the material before soaking in SBF. The change in calcium ion concentration during the test cycle in the bioceramic – SBF system was confirmed with UV/VIS spectrophotometry. The most significant increase in concentration was recorded on the third day of soaking. The assumption of an apatite layer formation on the soaked bioceramic samples was supported by a change in the concentration of calcium ions SBF and the change in weight of the material after soaking. It was found that using indirect colorimetric determination delivered better results when the Murexide indicator was used instead of KIT.
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Characterization of plant-based component of selected foodstuffs using techniques of molecular biology and instrumental methods
Tomíšek, Martin ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The aim of this work was to compare authenticity analysis in selected food products with fruit component by using, instrumental and molekular methods. Particularly, the presence of blueberries in fruit–based foodstuffs was verified. The theoretical part is focused on the characterization, chemical composition and botanical classification of blueberries (European blueberry and Canadian blueberry). It also contains an overview of instrumental and molecular diagnostic methods that can be used for the analysis of these fruits. The experimental part focuses on the selection of a suitable method of DNA isolation, and primers for the detection of blueberries in commercial products. DNA analysis was performed by qPCR and HRM analysis. In the experimental part, DNA was isolated in sufficient quality for PCR and the presence of blueberries in foodstuffs was verified by qPCR. Using HRM analysis, we were able to differentiate between bilberry (Vaccinium myrtillus) and blueberry (Vaccinium corymbosum) in control samples and in some commercial products. Certain phenolic acids and some flavonoids specific for blueberries were detected by HPLC. The total content of polyphenols and flavonoids was determined by UV / VIS spectrophotometry.
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Analysis of juices of selected red and white currant varieties
Černá, Anna ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
Presented diploma thesis deals with the analysis of juices of selected red and white currant varieties. The theoretical part is dedicated to the characteristics of a currant, biologically active substances of its fruits, its growing proces and the utilization of currants in the food industry. The analyzed parameters of currants - phenolics, anthocyanins and vitamin C are also characterized in the theoretical part with possibůe methods of their determination. The experimental part is devoted to the preparation of samples and the working practices of individual analysis. Six selected varieties of white and eleven varieties of red currant from Research and Breeding Institute of Pomology Holovousy Ltd. and six varieties of white and ten varieties of red currant from private grower were used for the analysis. Total phenolics and anthocyanins were determined spectrophotometrically, the content of vitamin C was determined by HPLC. Higher values of these compounds were measured mainly in the varieties of Research and Breeding Institute of Pomology Holovousy Ltd. Varieties of red currants contained higher amounts of total phenolics and anthocyanins while white currants contained higher amounts of vitamin C.
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Determination of pKa of humic acids by means of UV/VIS spectrometry
Kratochvílová, Romana ; Maršálek,, Roman (referee) ; Klučáková, Martina (advisor)
The behaviour of humic acids in aqueous solutions is closely connected to the content of acid functional groups and their dissociation abilities. The titration methods are the most often used for the research of acid-base characteristics of humic acids, their results should lead to the determination of the content of functional groups and their pKa. However the determined values depend on many factors including the titration speed. The spectrophotometric determination of dissociation constant was used in this diploma thesis. Reliability of this method was confirmed in bachelor thesis where is mentioned that spectrophotometric determination of pKa corresponds with realistic dissociation behaviour of humic acids in the water much more better than values obtained from titration methods. The principle of newly used spectrophotometry method is the preparation of humic acids solutions in three different media with different pH values. Acid groups of humic acids are practically completely dissociated in intensely basic environment and the measured absorbance is caused by anion of „humate“. On the contrary their dissociation in acid environment is suppressed so much that we measure the absorbance of non-dissociated molecules of humic acids. Deionized water was used like neutral solvent. Water was replaced by acetic buffer in this thesis because of water’s properties which have significant influence on solutions' pH. Buffer was used for diluting or for solubilisation and in these both cases more stable pH values were occurred. The aim of this diploma thesis is investigate UV/VIS spectra of various solutions of humic acids with different values of pH and determinate mean value of pKa of humic acids which could be used like comparison of dissociation behaviours for vary samples. Values of acid dissociation constant were determined from measured dates and compared with values obtained by titration method. The UV/VIS spectra gained in combination with the results of pH measuring and the conductivity next showed the differences in the behaviour of differently prepared samples of humic acids.
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