National Repository of Grey Literature 82 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Determination of zearalenone in malting barley
Wawroszová, Simona ; Čumová,, Martina (referee) ; Běláková, Sylvie (advisor)
This bachelor thesis deals with monitoring of zearalenone content in malting barley using immunochemical method ELISA and consequently method of liquid chromatography with mass spectrometry (LC-MS/MS). Theoretical part describes the brewing raw materials and important toxinogenic filamentous fungi. Special attention was drawn to selected fusarium mycotoxins (fumonisins, trichothecenes, zearalenone). It also describes some methods for determination of mycotoxins. Experimental section describes analyze 90 samples of malting barley of different varieties using method ELISA. In 19 samples zearalenone concentration was higher than limit of quantification. The highest level of zearalenone concentration (39,2 g•kg-1) contained barley, variety Wintmalt, where corn was used as a fore-crop. The samples were subsequently analyzed by LC-MS/MS. Zearalenone concentration was higher than limit of quantification only in four samples, namely in samples of Blaník, Malz and Wintmalt varieties of barley. Furthermore, the samples of intermediate products of malting process were analyzed by LC-MS/MS. No sample showed level of zearalenone higher than limit of quantification.
The multiresidue determination of pesticides in barley and malt by the LC/MS method with QuEChERS extraction
Posoldová, Kateřina ; Pernica,, Marek (referee) ; Mikulíková, Renata (advisor)
The topic of this thesis is the determination of pesticides in barley and malt. Barley is one of the second most cultivated cereals in the Czech Republic. In order to achieve higher yields, higher grain quality, and avoid losses, plant protection products - pesticides - are used. The disadvantage of their use is their negative impact on human and animal health and the environment. Residues of pesticides and their metabolites can remain in a food, so it is a good idea to monitor their content. There are various options for determination, but recently the QuEChERS extraction method has been used, which speeds up the whole sample preparation process. The practical part summarizes the optimization and validation of the QuEChERS method and the subsequent quantification of analytes by UPLC-MS/MS. The content of 148 pesticides in 30 barley and 20 malt samples from the 2021 harvest in the Czech Republic was analysed.
Dependence of quality parameters of malt on the temperature of mashing at sweet wort preparation
Zlámalová, Petra ; Sachambula, Lenka (referee) ; Mikulíková, Renata (advisor)
The Masters thesis deals with dependence of quality parameters of malt on the temperature of mashing at sweet wort preparation. The theoretical part focuses on the technology of malt production including description of ingredients, production parts, some kinds of malt and the quality parameters. There is also described the technology of sweet wort preparation and the methods of determination of the malt quality parameters in the sweet wort there. The experimental part focuses on determination of malt extract, viscosity, haze, colour, time of starch cleavage, pH, degree of fermentation and beta-glucans content. Based on temperature dependence of parameters, the individual samples were compared and the effects of temperature were discussed. The biggest extract of light and caramel malts was explored at 70 °C, of coloured malt at 50 °C. The lowest viscosity of light and coloured malts was explored at 65 °C, of caramel malt at 50 °C. The lowest haze of wort was at 65 °C. Ideal colour of all malts was at all mashing temperatures. Ideal pH of all malts was explored at 70 °C. Ideal time of starch cleavage was explored at 70-85 °C. The biggest achievable degree of fermentation and the hugest increase of beta-glucans content were explored at 65 °C.
Spiral conveyor
Nekoksa, Pavel ; Kašpárek, Jaroslav (referee) ; Malášek, Jiří (advisor)
This bachelor thesis deals with the design and construction design spiral conveyor. In the text part is performed design calculation of the major parts of spiral screw conveyor, drive unit design, storage worm screw, strength check of functional parts and an appropriate choice of material transported. Design documentation based on text part and consists of a conveyor assembly drawing, a list of items and drawing worm screw.
Enzyme content monitoring in wheat malt
Šubertová, Hana ; Benešová, Karolína (referee) ; Hartman,, Ivo (advisor)
The aim Master thesis was to evaluate the influence of malting technology on the content of hydrolytic enzymes -amylase and -amylase. Another aspect of this thesis was to select a wheat variety with the highest activity of enzymes -amylase and -amylase. The first part of the practical part of my work is shown measuring enzyme malt model varieties of wheat set (Triticum aestivum), where individual samples differ technological processing of malting and the second part is focused on the application of efficient malting conditions on other varieties from different locations in the Czech Republic in 2016 . All malt samples were analysed to -amylase and -amylase activity by assay Ceralpha method and Betamyl-3 method made by Megazyme company. After measuring the first part, the most effective malting condition was evaluated, such as a 7 day malting time, a 45% water content, a germination temperature of 18 ° C, and a drying temperature of 50 ° C. In the second part, the varieties are so malted and the highest content of enzyme -amylase was Rumor, it had averafe contanin -amylase 277 U/g, Bonanza – 255 U/g and Izzy –254 U/g. The biggest contain of enzymes -amylasehad varieties Matchball – 37,9 U/g , Fakir – 35,6 U/g, and Bernstein – 35,3 U/g.
Introducing of method of pyridoxine determination by liquid chromatography in food products and resources
Nechyba, Ondřej ; Benešová, Karolína (referee) ; Vespalcová, Milena (advisor)
This master‘s thesis deals with quantification of vitamin B6 in beverages, food supplements and raw materials in food industry. The literature retrieval part summarizes general information about vitamines, vitamine B6, nicotine acid and vitamine B1. Further on in this part there is described principle of high pressure liquid chromatography and quantification of individual vitamines. In the experimental there are listed used tools, apparatus and chemicals. There is described preparation of idividual samples of food supplements, energy drinks, multivitamine drinks, beers and brewer’s malts. This chapter also contains information about chromatographic separatory systems Shimadzu and SpectraSystem. The quantification was performed by high pressure liquid chromatography on a reverse phase with gradient elution and two ways of detection, fluorescent and spectrofotmetric. The result of experimental activities and vitamine content in analysed samples are presented in the next chapter. In the final contains summarization of results obtained in experimental part. The maser’s thesis was measured in the laboratory of Institute of Food Science and Biotechnology, Faculty of Chemistry, Brno University of Technology.
Determination of ergosterol content in brewing materials
Matyáš, Martin ; Ing.Pavla Kožušníková, Ph.D. (referee) ; Benešová, Karolína (advisor)
Presented bachelor’s thesis is focused on determination of ergosterol content in barley and malt. In theoretical part the presence of ergosterol in barley and malt has been elaborated, the purposes of its determination, detailed overview of previously applied methods of extraction from samples of barley and malt as well as other biological materials and methods of quantification. Practical part is focused on optimizing of extraction and determination of ergosterol by high performance liquid chromatography with diode array detection (HPLC – DAD).
Changeof phenolic acids content during malting of spring barley
Štýblová, Romana ; Janoušková, Eva (referee) ; Běláková, Sylvie (advisor)
This bachelor thesis deals with detection of chosen phenolic acids (sinapic acid, caffeic acid, ferulic acid, syringic acid, p – hydroxybenzoic acid, vanillic acid and p – coumaric acid) in the malting barley and monitoring of their changes during making a malt in real enviroment of floor malt house. Tehoretical part describes individual phenolic acids, their presentation in raw material for making of malt and methods for determination . There is described technology of making a malt. The nine samples was taken in experimental part. There were a malting barley, intermediate products of malting, malt and rootlets. Phenolic acids were extracted by alkaline and acid hydrolysis. This samples were detected by Ultra high – performance liquid chromatography using of UV detection (UPLC/PDA).
Determination of beta-glucans and pentosans in raw materials for production of beer and in beer
Piškulová, Lenka ; Sachambula, Lenka (referee) ; Mikulíková, Renata (advisor)
The content of beta-glucans and arabinoxylans in barley grain, malt and wort was monitored. The varieties of barley were Pionier, Libuše, Manta, Tango, KWS Amadora, Kampa, KWS Irina, Francin, Odyssey, Overture, Vendela, Petrus, Laudis 550, Sunshine, Kangoo, Xanadu, Sebastian, Bojos and Malz. These varieties were grown on three different habitats (Uherský Ostroh, Věrovany and Vysoká u Příbramě). The content of beta-glucans and arabinoxylans was also analysed in five different types of beer. In brewing and malting industry the content of beta-glucans and arabinoxylans is mainly monitored because of their negative influence on decanting of wort and filtration of beer. These substances can contribute to turbidity and precipitation in beer and thus negatively effect the stability of beer. The content of beta-glucans in barley grain, malt, wort and beer was determined by FIA method and the content of arabinoxylans was determined in barley grain, wort and beer by Douglas method. The highest content of beta-glucans in barley grain was found in 14/19 varieties at Uherský Ostroh, where the amount of beta-glucan content was in the range of 3,65-5,60 %. The highest beta-glucan content in malt was found in 17/19 varieties at Vysoká u Příbramě, where the beta-glucan content was between 0,15-0,79 % and the highest content of beta-glucans in wort was found in 16/19 varieties also at Vysoká u Příbramě. There was the beta-content in the range of 22-184 mg/l. The results of content of arabinoxylans in barley grain and wort were more balanced. The highest content of arabinoxylans in barley grain was found in 10/19 varieties at Věrovany. The content of arabinoxylans at this habitat was in the range of 3,04-4,56 %. The highest content of arabinoxylans in wort was determined in 8/19 varieties at Uherský Ostroh. The content of arabinoxylans at this habitat was in the range of 542-1040 mg/l. The highest content of beta-glucans in samples of beer was determined in a sample of light lager (207 mg/l) and the highest content of arabinoxylans was found in a samle of wheat lager (1465 mg/l).
Monitoring of 3-MPCD content in barley, malt and beer
Šálková, Michaela ; Svoboda, Zdeněk (referee) ; Mikulíková, Renata (advisor)
The master’s thesis focuses on a process contaminant 3-MCPD (3-chloropropane-1,2-diol), which is formed during food processing. The first part of the thesis summarizes scientific knowledge about its chemical and physical properties, toxicity, occurrence in food and methods of analysis. In the second part is monitored the content of 3-MCPD in barley, in standard and special types of malts and beer. Samples were derivatized with phenylboronic acid (PBA) and 3-MCPD derivatives were analyzed by gas chromatography with a mass detector. Deuterated 3-MCPD was used as an internal standard. The limit of quantification was 1 gkg-1 for barley and malt samples and 10 gkg-1 in case of beer. The barley samples contained concentration of 3-MCPD below LOQ. In samples of malt was found concentration

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