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Beer proteome analysis by mass spectrometry
Müller, Lukáš ; Havliš,, Jan (referee) ; Zdráhal, Zbyněk (advisor)
The aim of presented diploma thesis was to characterize recent knowledge in the field of beer proteomics. The main part of this work was focused on modern instrumental methods of protein analysis, especially on protein identification by mass spectrometry. In experimental part proteins from selected beer samples were isolated, purified and separated by 2-D electrophoresis. The identification was performed by MALDI MS/MS and LC-MS/MS. Identified proteins were divided into 6 groups - serpines and protein Z, trypsine/-amylase inhibitors, yeast proteins, LTP protein, hordeins and other proteins. Proteomic analysis provided identification of proteins important for final analytical and sensory characteristics of the beer - for final beer quality and taste
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Monitoring of the content of selected trichothecene mycotoxins in malting barley
Hrdinová, Lucie ; Kočí, Radka (referee) ; Běláková, Sylvie (advisor)
This master thesis deals with a monitoring of a content of the trichothecene mycotoxins deoxynivalenol, nivalenol, T-2 toxin and HT-2 toxin in malting barley using the LC-MS/MS method. The theoretical part describes general characteristics of mycotoxins and their significant producer filamentous fungus of Fusarium species. Further, important trichothecene mycotoxins and mycotoxins generally which are commonly found in malting barley were also characterized. In the theoretical part of the thesis possibilities for a determination of the mycotoxins by the chromatographic methods were presented too; the immunochemical methods were also mentioned. In the experimental section an analysis of the B type trichothecenes was optimized by LC/APCI-MS/MS and of the A type trichothecenes by LC/ESI-MS/MS. When analyzing 57 samples of different barley varieties the deoxynivalenol reached the highest values (up to 945,2 µg.kg-1), namely in the case of the Sebastian variety with corn as the fore-crop. The highest values of nivalenol, T-2 toxin and HT-2 toxin (138,4 µg.kg-1; 21,8 µg.kg-1 and 68,7 µg.kg-1 respectively) were found in the Prestige variety of barley with winter wheat as the fore-crop. Subsequently a second set of four experimental samples of the Sebastian variety of barley and malt produced from the variety with corn as the fore-crop were analysed. In this group three samples were artificially infected with the filamentous fungi of Fusarium species; the fourth sample was not artificially infected and served as a control sample. Even in the case of the artificially infected samples the deoxynivalenol reached the highest values. The master thesis was implemented in the Research Institute of Brewing and Malting, Plc. in Brno.
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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.
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Determination of diquat and paraquat in agricultural commodities
Prchal, Miroslav ; Hrbek,, Vojtěch (referee) ; Petra,, Kosubová (advisor)
This diploma thesis focuses on polar pesticides and their analysis in agricultural commodities. One of the aims was establishing of the method for quantitative determination of diquat and paraquat using liquid chromatography with tandem mass spectrometry. Optimization parameters based on the European reference laboratories recommendations, availability of laboratory equipment and method suitability for routine analyses were taken into account. Extraction of analytes was based on shaking with acidified methanol with formic or hydrochloric acid. Considering the matrix complexity, purification with sorbents and/or acetonitrile precipitation were applied. Method validation was carried out on several levels for selected representative agricultural commodities. Part of the thesis is a field experiment where potatoes plants were sprayed with the diquat active substance. Samples of treated plants and tubers were analyzed for diquat residues. The validated method was also used for screening of diquat and paraquat residues in feed samples collected within official controls of the Central Institute for Supervising and Testing in Agriculture in 2020. The final method enables to analyze diquat and paraquat with sensitivity suitable for the maximal residue limit controls.
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Mycotoxins in Brewing Materials and Beer
Běláková, Sylvie ; Vávrová, Milada (referee) ; Márová, Ivana (referee) ; Kráčmar, Stanislav (referee) ; Čáslavský, Josef (advisor)
The presented thesis deals with the issue of mycotoxins in brewing materials and beer. Attention was devoted mainly to the selected fusarium mycotoxins (deoxynivalenol, zearalenol, T-2 toxin, and HT-2 toxin) ochratoxin A and aflatoxins B1, B2, G1, and G2. The aim of the thesis was to optimize and validate analytical methods for the determination of the above mentioned mycotoxins in the brewing materials and beer. Analytes were separated using high-performance liquid chromatography with mass – spectrometric detection (HPLC-MS/MS) and ultra-performance liquid chromatography with fluorescence detection (UPLC/FLR). These analytical methods were then applied for mapping the occurrence of fusarium mycotoxins in malting barley crops in the Czech Republic and monitoring the level of contamination with mycotoxins in malting and brewing industries. In addition, experiments studying over-foaming of beer were conducted as primary gushing – over-foaming of beer – is connected, similarly as mycotoxins, with the presence of microscopic filamentous fungi in the raw materials for beer production. Studies describing in detail these methods are part of this thesis (Annex I – V). From all published results, it is evident that the occurrence of mycotoxins in cereals including barley is natural and cannot be completely prevented, not even if all conditions of correct agricultural practice are observed. It is known that some mycotoxins present in contaminated malting barley pass to the final product – beer due to their chemical and physical properties. However, the mycotoxin concentrations found do not mean any significant health risk for consumers.
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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.
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Determination of diquat and paraquat in agricultural commodities
Prchal, Miroslav ; Hrbek,, Vojtěch (referee) ; Petra,, Kosubová (advisor)
This diploma thesis focuses on polar pesticides and their analysis in agricultural commodities. One of the aims was establishing of the method for quantitative determination of diquat and paraquat using liquid chromatography with tandem mass spectrometry. Optimization parameters based on the European reference laboratories recommendations, availability of laboratory equipment and method suitability for routine analyses were taken into account. Extraction of analytes was based on shaking with acidified methanol with formic or hydrochloric acid. Considering the matrix complexity, purification with sorbents and/or acetonitrile precipitation were applied. Method validation was carried out on several levels for selected representative agricultural commodities. Part of the thesis is a field experiment where potatoes plants were sprayed with the diquat active substance. Samples of treated plants and tubers were analyzed for diquat residues. The validated method was also used for screening of diquat and paraquat residues in feed samples collected within official controls of the Central Institute for Supervising and Testing in Agriculture in 2020. The final method enables to analyze diquat and paraquat with sensitivity suitable for the maximal residue limit controls.
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Mycotoxins in Brewing Materials and Beer
Běláková, Sylvie ; Vávrová, Milada (referee) ; Márová, Ivana (referee) ; Kráčmar, Stanislav (referee) ; Čáslavský, Josef (advisor)
The presented thesis deals with the issue of mycotoxins in brewing materials and beer. Attention was devoted mainly to the selected fusarium mycotoxins (deoxynivalenol, zearalenol, T-2 toxin, and HT-2 toxin) ochratoxin A and aflatoxins B1, B2, G1, and G2. The aim of the thesis was to optimize and validate analytical methods for the determination of the above mentioned mycotoxins in the brewing materials and beer. Analytes were separated using high-performance liquid chromatography with mass – spectrometric detection (HPLC-MS/MS) and ultra-performance liquid chromatography with fluorescence detection (UPLC/FLR). These analytical methods were then applied for mapping the occurrence of fusarium mycotoxins in malting barley crops in the Czech Republic and monitoring the level of contamination with mycotoxins in malting and brewing industries. In addition, experiments studying over-foaming of beer were conducted as primary gushing – over-foaming of beer – is connected, similarly as mycotoxins, with the presence of microscopic filamentous fungi in the raw materials for beer production. Studies describing in detail these methods are part of this thesis (Annex I – V). From all published results, it is evident that the occurrence of mycotoxins in cereals including barley is natural and cannot be completely prevented, not even if all conditions of correct agricultural practice are observed. It is known that some mycotoxins present in contaminated malting barley pass to the final product – beer due to their chemical and physical properties. However, the mycotoxin concentrations found do not mean any significant health risk for consumers.
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Monitoring of the content of selected trichothecene mycotoxins in malting barley
Hrdinová, Lucie ; Kočí, Radka (referee) ; Běláková, Sylvie (advisor)
This master thesis deals with a monitoring of a content of the trichothecene mycotoxins deoxynivalenol, nivalenol, T-2 toxin and HT-2 toxin in malting barley using the LC-MS/MS method. The theoretical part describes general characteristics of mycotoxins and their significant producer filamentous fungus of Fusarium species. Further, important trichothecene mycotoxins and mycotoxins generally which are commonly found in malting barley were also characterized. In the theoretical part of the thesis possibilities for a determination of the mycotoxins by the chromatographic methods were presented too; the immunochemical methods were also mentioned. In the experimental section an analysis of the B type trichothecenes was optimized by LC/APCI-MS/MS and of the A type trichothecenes by LC/ESI-MS/MS. When analyzing 57 samples of different barley varieties the deoxynivalenol reached the highest values (up to 945,2 µg.kg-1), namely in the case of the Sebastian variety with corn as the fore-crop. The highest values of nivalenol, T-2 toxin and HT-2 toxin (138,4 µg.kg-1; 21,8 µg.kg-1 and 68,7 µg.kg-1 respectively) were found in the Prestige variety of barley with winter wheat as the fore-crop. Subsequently a second set of four experimental samples of the Sebastian variety of barley and malt produced from the variety with corn as the fore-crop were analysed. In this group three samples were artificially infected with the filamentous fungi of Fusarium species; the fourth sample was not artificially infected and served as a control sample. Even in the case of the artificially infected samples the deoxynivalenol reached the highest values. The master thesis was implemented in the Research Institute of Brewing and Malting, Plc. in Brno.
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Beer proteome analysis by mass spectrometry
Müller, Lukáš ; Havliš,, Jan (referee) ; Zdráhal, Zbyněk (advisor)
The aim of presented diploma thesis was to characterize recent knowledge in the field of beer proteomics. The main part of this work was focused on modern instrumental methods of protein analysis, especially on protein identification by mass spectrometry. In experimental part proteins from selected beer samples were isolated, purified and separated by 2-D electrophoresis. The identification was performed by MALDI MS/MS and LC-MS/MS. Identified proteins were divided into 6 groups - serpines and protein Z, trypsine/-amylase inhibitors, yeast proteins, LTP protein, hordeins and other proteins. Proteomic analysis provided identification of proteins important for final analytical and sensory characteristics of the beer - for final beer quality and taste
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