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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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Monitoring of the occurrence of mycotoxins in beers from market retail
Wawroszová, Simona ; Pospíchalová, Markéta (referee) ; Běláková, Sylvie (advisor)
This master thesis deals with monitoring of a content of deoxynivalenol, its metabolite deoxynivalenol-3-b-D-glucopyranoside and ochratoxin A in beer samples collected from retail market in the Czech Republic, Poland and Slovakia. The theoretical part describes general characteristics of mycotoxins, its transfer from field barely through malt to beer and its occurrence in beers. Malting process and brewing technology were also mentioned. Subsequently possibilities for a determination of the mycotoxins by the chromatografic and immunochemical method were presented. The experimental section describes analysis of 30 samples of beer. The analyses were conducted using ultra high-performance liquid chromatography with fluorimetric detection (UPLC/FLR) for ochratoxin A and high-performance liquid chromatography coupled with mass spectrometer (HPLC/MS) for deoxynivalenol and its metabolite. Ochratoxin A was detected in 25 of the 30 samples in concentration range of 0,6 - 82,5 ng·l-1. Deoxynivalenol was found in 24 of the 30 samples with concentration range of 2,29 - 12,57 ug·l-1 and deoxynivalenol-3-b-D-glucopyranoside was occure in 19 of the 30 samples in concentration range of 2,45 - 12,47 ug·l-1. It was also assessed the relationship between beer gushing and presence of mycotoxins in beer. No connection between the parameters has been found. Consequently it is not possible to predict beer gushing from the presence of mycotoxins.
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The content of chosen mycotoxins in feeds
Zelníčková, Lenka ; Babák, Libor (referee) ; Kellnerová, Dita (advisor)
This diploma thesis is focused on current problematics of monitoring of selected mycotoxins, DON and ZEA, in feeds in Czech Republic. The objective of my thesis was to elaborate a literature search from available books, electronic and periodical sources and service materials. Literature search is aimed at overall overview of mycotoxins, describes their characteristics, biological effects, methods of detection as well as summarizes recent legislation requirements concerning occurrence of these substances in feeds for animals. The aim of experimental part was a determination of selected mycotoxins in feed (DON and ZEA) by ELISA method and their evaluation according to the maximum limits. The diploma thesis was prepared in diagnostic laboratory SEVARON, s. r. o. in Brno.
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Methods for the extraction of selected toxins from solid matrices and their subsequent determination by HPLC/MS
Herman, David ; Zlámalová Gargošová, Helena (referee) ; Čáslavský, Josef (advisor)
This diploma thesis is focused on the analysis of toxins and their extraction from sandyloamy soil. Particularly, saxitoxin and trichothecene mycotoxins deoxynivalenol, HT-2 and T-2 toxins are in the centre of interest of this work. Their occurrence, toxic properties and influence on living organisms are described in theoretical part of this thesis. In next chapters, currently published extraction methods for individual toxins and analytical approaches for their quantitative evaluation are summarized. In experimental part of this thesis, optimized process of sample pretreatment based on extraction of toxins from soil using 1mM HCOONH4 in 84% acetonitrile was proposed as the best option. Simultaneous determination of toxins was performed by liquid chromatography on a CN column (3.0 x 150 mm, 3 m, 100 ) in gradient elution mode. Mass spectrometer with electrospray as ion source and linear ion trap as analyzer was used as detector. Recovery of designed method was over 80% for trichothecene mycotoxins and 51% for saxitoxin.
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Stability of selected mycotoxins in beer
Štáblová, Taťána ; Benešová, Karolína (referee) ; Běláková, Sylvie (advisor)
Mycotoxins are secondary metabolites of moulds, which attack cereals, for example barley, from which mycotoxins then get to beer. This submitted work is focused on ochratoxin A, deoxynivalenol and zearalenone, which can occur in beer. The first part of this master’s thesis consists of literary research, which describes mycotoxins in general, points out their occurrence, prevention of their formation and delivers information about their physical and chemical properties and toxicity. Furthermore, the research contains basis of malt and beer technology, the occurrence of mycotoxins in beer and raw materials for its production. The research describes changes in concentration of mycotoxins across malt and beer production. The next part deals with possibilities of determination of mycotoxins in barley, malt and beer, compares individual methods of their determination and points out many difficulties of some analyses. The experimental part of this work pursues determination of ochratoxin A, deoxynivalenol and zearalenone in different types of beer with the help of UPLC-FLR, HPLC-MS and ELISA. Instrumental techniques are validated and gathered results are compared with the results in literature. The goal of this master’s thesis is to assess the stability of ochratoxin A and deoxynivalenol in beer over time. The gained results show that there are changes in the concentration of ochratoxin A over time, nevertheless those changes show no pattern. Overall, there was a decrease in concentration in 47 % of the samples and an increase in 28 % of them. In the rest of the samples the concentration did not change. The concentration of deoxynivalenol does not change over time. One of the other goals of this thesis is monitoring of selected mycotoxins in beer. The average concentration of ochratoxin A in the samples was 39 ng/l and deoxynivalenol 9,9 g/l. Zearalenone did not occur in any of the samples when determined by liquid chromatography. All results agree with literature. Next, the thesis compares different analytical methods for determination of ochratoxin A, deoxynivalenol and zearalenone. The screening method ELISA is compared to UPLC-FLR and HPLC-MS. The determination of ochratoxin A by ELISA has shown to be time consuming, nevertheless the results responded to instrumental technique. ELISA overestimated the results of determination of deoxynivalenol in beer by 363–697 % and with zearalenone there were found false positive results.
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Průnik obsahu mykotoxinů ze zrna obilovin do hotového výrobku a dopad na zdraví člověka
Machálková, Monika
This thesis deals with the issue of mycotoxins, which are important pathogens of many agricultural crops and may pose a high health risk to humans and livestock. It contains an overview of the most important mycotoxins their producers and mycotoxicoses. The main focus of this thesis is the occurrence of mycotoxins in cereals and the effect of processing it on their content. The experimental part focuses on monitoring the content and the penetration of deoxynivalenol and zearalenone in winter wheat from grain to bread. We examined a total of 10 samples of treated and 10 samples of untreated variants of winter wheat. For each sample grain, flour and bread were examined for DON and ZEA content and all tested samples were positive for DON and ZEA. None of the examined samples exceeded or even approached the legislative limits.
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Metody stanovení mykotoxinů v obilninách
Trifković, Miloš
Mycotoxins which are associated with Fusarium spp. and disease caused by this genus, Fusarium Head Blight (FHB), on grains represents a global issue for food and feed security. In order to determinate if the BoMill IQ is capable to recognize the content of mycotoxin in grains of barley, we were testing three different varieties fromm five firms, in two repetitions. This technology uses Near Infrared Transmittance (NIT) to distinguish kernels containing mycotoxins form healthy based on individual kernel protein content. Correlations between content of proteins and tested mycotoxins (deoxynivalenol and nivalenol) were observed. We have found strong negative correlations between both mycotoxins and content of proteins, but there was a strong positive correlation between deoxynivalenol and nivalenol. Results showed that this technology can be used to determinate content of mycotoxins in individual kernels and to sort the grains in different fractions which differ in content of mycotoxins.
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Stability of selected mycotoxins in beer
Štáblová, Taťána ; Benešová, Karolína (referee) ; Běláková, Sylvie (advisor)
Mycotoxins are secondary metabolites of moulds, which attack cereals, for example barley, from which mycotoxins then get to beer. This submitted work is focused on ochratoxin A, deoxynivalenol and zearalenone, which can occur in beer. The first part of this master’s thesis consists of literary research, which describes mycotoxins in general, points out their occurrence, prevention of their formation and delivers information about their physical and chemical properties and toxicity. Furthermore, the research contains basis of malt and beer technology, the occurrence of mycotoxins in beer and raw materials for its production. The research describes changes in concentration of mycotoxins across malt and beer production. The next part deals with possibilities of determination of mycotoxins in barley, malt and beer, compares individual methods of their determination and points out many difficulties of some analyses. The experimental part of this work pursues determination of ochratoxin A, deoxynivalenol and zearalenone in different types of beer with the help of UPLC-FLR, HPLC-MS and ELISA. Instrumental techniques are validated and gathered results are compared with the results in literature. The goal of this master’s thesis is to assess the stability of ochratoxin A and deoxynivalenol in beer over time. The gained results show that there are changes in the concentration of ochratoxin A over time, nevertheless those changes show no pattern. Overall, there was a decrease in concentration in 47 % of the samples and an increase in 28 % of them. In the rest of the samples the concentration did not change. The concentration of deoxynivalenol does not change over time. One of the other goals of this thesis is monitoring of selected mycotoxins in beer. The average concentration of ochratoxin A in the samples was 39 ng/l and deoxynivalenol 9,9 g/l. Zearalenone did not occur in any of the samples when determined by liquid chromatography. All results agree with literature. Next, the thesis compares different analytical methods for determination of ochratoxin A, deoxynivalenol and zearalenone. The screening method ELISA is compared to UPLC-FLR and HPLC-MS. The determination of ochratoxin A by ELISA has shown to be time consuming, nevertheless the results responded to instrumental technique. ELISA overestimated the results of determination of deoxynivalenol in beer by 363–697 % and with zearalenone there were found false positive results.
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Monitoring of the occurrence of mycotoxins in beers from market retail
Wawroszová, Simona ; Pospíchalová, Markéta (referee) ; Běláková, Sylvie (advisor)
This master thesis deals with monitoring of a content of deoxynivalenol, its metabolite deoxynivalenol-3-b-D-glucopyranoside and ochratoxin A in beer samples collected from retail market in the Czech Republic, Poland and Slovakia. The theoretical part describes general characteristics of mycotoxins, its transfer from field barely through malt to beer and its occurrence in beers. Malting process and brewing technology were also mentioned. Subsequently possibilities for a determination of the mycotoxins by the chromatografic and immunochemical method were presented. The experimental section describes analysis of 30 samples of beer. The analyses were conducted using ultra high-performance liquid chromatography with fluorimetric detection (UPLC/FLR) for ochratoxin A and high-performance liquid chromatography coupled with mass spectrometer (HPLC/MS) for deoxynivalenol and its metabolite. Ochratoxin A was detected in 25 of the 30 samples in concentration range of 0,6 - 82,5 ng·l-1. Deoxynivalenol was found in 24 of the 30 samples with concentration range of 2,29 - 12,57 ug·l-1 and deoxynivalenol-3-b-D-glucopyranoside was occure in 19 of the 30 samples in concentration range of 2,45 - 12,47 ug·l-1. It was also assessed the relationship between beer gushing and presence of mycotoxins in beer. No connection between the parameters has been found. Consequently it is not possible to predict beer gushing from the presence of mycotoxins.
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Průnik obsahu mykotoxinů ze zrna obilovin do hotového výrobku a dopad na zdraví člověka
Machálková, Monika
This thesis deals with the issue of mycotoxins, which are important pathogens of many agricultural crops and may pose a high health risk to humans and livestock. It contains an overview of the most important mycotoxins their producers and mycotoxicoses. The main focus of this thesis is the occurrence of mycotoxins in cereals and the effect of processing it on their content. The experimental part focuses on monitoring the content and the penetration of deoxynivalenol and zearalenone in winter wheat from grain to bread. We examined a total of 10 samples of treated and 10 samples of untreated variants of winter wheat. For each sample grain, flour and bread were examined for DON and ZEA content and all tested samples were positive for DON and ZEA. None of the examined samples exceeded or even approached the legislative limits.
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