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Porovnání metod stanovení obsahu mykotoxinů v obilninách
Boving, Veronique
In the Bachelor thesis I have dealt with a comparison of methods for determination of mycotoxins in cereals. The first part is a recent survey, in which I described the distribution of mycotoxins, I described the toxigenic fungi and produced mycotoxins. I noted the characteristics of the best-known mycotoxin and described some of the analytical method for the determination of mycotoxins. In the second part I focused on analysis of cereal samples. A total of 12 samples were analyzed by parallel analysis, that should determine the accuracy of the measurement. Analysis was performed using three methods of analysis, and ROSA for ZEA and DON, Reveal Q + for DON DON DON RAPID, Veratox for ZEA and the reference method was HPLC method. Difference was observed in the parallel measurements, the results of mycotoxins analyzed by various methods differed. We can not say which method is more accurate.
Analytické a senzorické možnosti kontroly falšování pravosti révového vína
Rozek, Kamil
The diploma thesis deals with analytical and sensorial possibilities of control of grape wine adulteration. In the first, theoretical part of the thesis, the author introduces valid legislation regulating authorized substances in wine, as well as the wine production processes itself. The reader is acquainted with the means of wine adulteration in the Czech Republic that ensued from an analysis of unsatisfactory samples of wine, collected between 2012 -- 2015 by the SZPI (Czech Agriculture and Food Inspection Authority). The second, practical part of the thesis, describes not only grape wine and SZPI samples imitation production processes, but also methods used for their subsequent sensorial and analytical study. Besides, it interprets measured data, and compares and contrasts the possibilities and appropriateness of the sensorial evaluation and analytical study for the detection of wine adulteration.
Determination of selected parameters in foreign beers
Punčochářová, Lenka ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
The aim of this thesis is determination of selected polyphenols, organic acids and elements (major and minor) in a foreign beers. Production of malt, beer production, beer types and beer styles are described in the theoretical part. Also analytical methods of beer analysis such as high performance liquid chromatography, iont chromatography and inductively coupled plasma optical emission spectrometry are described. The Experimental part deals with preparation of samples and calibration solutions, setting devices up and analysis of foreign beers samples. There were analyzed 14 foreign beers of which 11 samples were top-fermented beers, 3 samples were bottom-fermented. Four samples were produced in Belgium, three in England, three in Germany, two in the US, one in Holland and one in Poland. The results give an overview of the contents of compounds in foreign beers.
Draft beer analysis by HPLC-ELSD and IC
Vanduchová, Petra ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
In this bachelor thesis is discussed the brewing process and composition of the beer. The experimental part deals with analysis of polyphenolic compounds and carbohydrates by HPLC, analysis of organic acids by the IC and the ICP-OES method was used for analysis of elements. The HPLC method was used to determine eleven polyphenols. Gallic acid was the most represented compound of polyphenols and quercetin was the least represented compound. Glucose, fructose and sucrose were analysed by HPLC and the most represented compound of carbohydrates was glucose. The ICP-OES method was used to determine ten elements. Zinc was the least represented element in the analysis and phosphorus and potassium were the most represented in the analysis.
Determination of the basic physical and chemical parameters of fruit juice from aronia
Zídková, Anežka ; Jurečková, Zuzana (referee) ; Diviš, Pavel (advisor)
Theoretical part of bachelor´s thesis contains basic information about aronia (Aronia melanocarpa) and examples of their use. There is a description of analysed substances, which are contained in aronia berries, and their importance for human organism. Experimental part is focused on determination of minerals, saccharides and vitamin C in aronia juices, syrups, nectar and aronia wine. Elements were determined by inductively coupled plasma optical emission spectrometry. Liquid chromatography was chosen for analysis of saccharides and vitamin C. All of analysed products are significant sources of macroelements. The highest concentrations of elements were determined in the sample named Aroniový skorosirup, which was sugared by vaporized apple juice. Fructose and glucose were contained in all products. Sucrose was only in products which were sugared. The amount of vitamin C was lower in consequence of pasteurization and storage.
Determination of selected parameters in special types of beers brewed in the Czech Republic
Fähnrichová, Nikola ; Divišová, Radka (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with analysis of special types of beer brewed in the Czech Republic using three instrumental methods. Polyphenols were determined by high performance liquid chromatography. To determine organic acids was used ion exchange chromatography. Elementary analysis was performed by inductively coupled plasma optical emission spectrometry. The theoretical part of the work describes technology of beer production, chemical composition of beer, especially groups of substances which were analysed in this thesis. Principle of used methods is also described. The practical part of the work deals with preparation of tested samples, calibration samples and process analysis. The obtained results of analysed substances are summarized in the tables, discussed and compared with results of analysis of other authors. For the analysis it was used eighteen different types of special beer produced in the Czech Republic.
Determination of selected parameters in the Czech lager beer
Žáková, Kateřina ; Gregor,, Tomáš (referee) ; Diviš, Pavel (advisor)
The topic of this bachelor thesis is to establish an concentration of selected substances at czech beers lager type. In the first part of the work there are in a range of the theory described basic materials for a beer production and its production proces too. A large part is dedicated to describing of analytical methods used for an analysis of choosen phenolic substances, organic acids and inorganic substances (elements). In the experimental part the measured results are discussed. The target of this work was to compare a composition and to find specific or characteristic ingredients in selected brands type lager produced in Czech republic. Further there were compared the samples with the Czech Beer designation and the samples without those signing.
Possibilities of preparation combined drinks from selected fruits
Zábranská, Miroslava ; Vránová, Dana (referee) ; Vespalcová, Milena (advisor)
This thesis deals with the preparation of the combined alcoholic beverages based on wine and fruit juices. The fruit juices were obtained from the selected fruits as honeysuckle, mulberry, dogwood, rose hips, elderberry, buckthorn and aronia. Some chemical properties e. g. total fenolics, total anthocyanins, vitamin C and sacharides were determined for characterization of the mentioned juices. As well as chemical parameter of juices, the same chemical parameters were determined on wine. There were prepared three sets of combined beverages from wine and juices. The two best evaluated beverages were chosen on the basis of their sensory evaluation. In the end, the same chemical properties were determined in both particular juices and resulting beverages.
Analysis of selected substances contained in the extract from elderberry twigs
Škeřík, Jan ; Flodrová, Dana (referee) ; Šalplachta, Jiří (advisor)
My diploma thesis deals with the optimization and verification of conditions for separation of proteins, which are contained in the twigs of elder (Sambucus nigra L.) using the technique RP-HPLC. The measurements were made with the use of a HPLC system with a UV-VIS detector. Column Zorbax 300SB-C18 300 4,6 x 250 mm and particles the size of 5 microns were used. The theoretical part describes the attributes and usage of elder and especially its proteins. The basic characteristic of the used HPLC technique is introduced. The possibilities of how to identify proteins are described. The practical part demonstrates the individual steps of optimization of the HPLC method applied to the mixture of standard proteins. The application of this method in the real sample is also reported. The final part of the diploma thesis is focused on the comparison of analysed samples taken in different seasons.
Monitoring of the influence of yeasts on the chemical and sensory qualities of manufactured wine
Petrášová, Ludmila ; Vítová, Eva (referee) ; Vránová, Dana (advisor)
The thesis deals with monitoring of the yeast's impact to the chemical and sensorial characteristics of produced wine. The aim of experimental part was obtaining of the aroma-active substances in the fermenting must and wine Hibernal and wine Pinot Blanc. SPME-GC-MS methods were used for identify wines and must aroma. The same autochthonous yeasts were used for wine production. This yeast was isolated from surface of grapes in our laboratory. It was found that both wines have a similar aromatic profile. The next aim was the monitoring of chemical parameters of samples and their changes. For this measurement were used spectrophotometric methods and HPLC methods. The last goal of the thesis was the isolation and identification of yeasts from wine Pinot Blanc by PCR-RFLP. These yeasts were then compared with yeasts isolated from Hibernal must. Identification of yeasts were done by amplification 5,8S-ITS DNA stretches using primers ITS1 and ITS4. Restriction endonuclease HaeIII, HinfI, HhaI and TaqI. were used for restriction analysis then.

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