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Analysis of mycotoxins in barley and malt
Čuta, Robert ; Obruča, Stanislav (referee) ; Běláková, Sylvie (advisor)
This bachelor´s thesis deals with the mycotoxines present in cereals, especially in barley and malt. Teoretical part summarizes the knowledge of mycotoxines and their occurrence. The possibilities of mycotoxines determination are held forth in this thesis. In the experimental part an ultrasonic extraction metod of deoxynivalenol was optimized. For the deoxynivalenol determination was used a method of high-performance liquid chromatography with a mass detector (HPLC – MS/MS). This method was used for deoxynivalenol determination in barley and malt produced from this barley. The bachelor´s thesis was implemented in the Research Institute of Brewing and Malting, Plc. in Brno.
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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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Barley Proteomic Studies Related to Beer Production
Benkovská, Dagmar ; Márová, Ivana (referee) ; Ehrenbergerová, Jaroslava (referee) ; Zdráhal, Zbyněk (referee) ; Bobáľová, Janette (advisor)
Tato práce se zabývá proteomickými studiemi ječmene v souvislosti s výrobou piva. Ječmen patří mezi nejvýznamnější plodiny na světě a je využíván hlavně pro sladovnické účely, nejčastěji pro pivovarnictví. Studium proteinů ječmene během sladování a výroby piva poskytuje informace o změnách v proteinovém složení nebo jejich posttranslačních modifikacích. Jelikož jsou proteiny v ječmeni a jejich změny zásadní pro kvalitu sladu a piva, proteomické studie ječmene mají potenciál pro zlepšení procesu sladování a pivovarnictví. Hlavním cílem této práce je studium ve vodě rozpustných proteinů ječmene a jejich změn, ke kterým dochází během sladování a výroby piva. Rozdíly v proteinovém složení byly sledovány pomocí gelové elektroforézy, kapalinové chromatografie na reverzní fázi, gelové chromatografie a MALDI-TOF hmotnostní spektrometrie. Během sladování se vlivem klíčení zrna zvyšuje množství některých proteinů a také jsou tvořeny nové proteiny. V průběhu vaření piva se naopak v důsledku vysoké teploty a enzymatické aktivity proteáz mnoho proteinů rozkládá. Těmto drsným podmínkám odolají jen některé proteiny, které přechází až do piva a mohou ovlivnit jeho kvalitu. Dále byly zkoumány různé odrůdy ječmene a jejich rozdíly. Byly porovnány odrůdy povolené pro výrobu certifikovaného Českého piva s jednou osvědčenou sladovnickou odrůdou a jednou nesladovnickou odrůdou ječmene. Kromě toho byly studovány v alkoholu rozpustné proteiny ječmene a jejich změny v průběhu sladování. Zvláštní pozornost byla věnována vybrané skupině posttranslačních modifikací proteinů: glykosylacím. Neenzymaticky glykosylované proteiny ječmene (neboli glykované proteiny) jsou tvořeny v průběhu sladování kvůli přítomnosti velkého množství glukózy uvolněné z rozkladu škrobu. Glykované proteiny ovlivňují stabilitu proteinů a kvalitu piva, obzvlášť pěnotvorný účinek. Enzymatické N-glykosylace představují nejčastěji studované posttranslační modifikace u rostlin, protože glykoproteiny hrají klíčovou roli v různých biologických funkcích. Glykoproteiny jsou často přítomny v malém množství, a proto je pro jejich analýzu potřebné obohacení glykoproteinů z komplexní směsi. Pro studium glykoproteinů byla využita afinitní chromatografie s lektinem concanavalin A. Kromě toho byla také optimalizována analýza sacharidové části glykoproteinů. Tato disertační práce přináší důležité informace o proteinech ječmene, jejich změnách a analýze, které budou užitečné pro další studium.
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Monitoring of vitamin E content in the samples of cereals
Cibulcová, Pavla ; Borkovcová,, Ivana (referee) ; Benešová, Karolína (advisor)
Thesis deals with the analysis of vitamin E in cereal samples, namely barley and wheat and malt produced from them. Selected samples were treated with low-temperature plasma, fungicide and biological treatment to elimination fungus and mycotoxins. The aim of the thesis was to find out the influence of the treatment, the combination of several types of treatment on vitamin E content in grain and malt. If the content of health-positive substances is not reduced and grain can be used for food, malt, or for feed purposes. The theoretical part focuses on the properties, occurrence, biochemistry and importance of vitamin E for living organisms. It also focuses on the properties of cereals that are a significant source of vitamin E. Malt production and sample treatment are also described. The experimental part describes the field experiment, individual types of treatment, extraction of vitamin E from the samples and determination of vitamin E content by high performance liquid chromatography with fluorescence detection. The results are compared with the current literature. It was found that the treatment did not have a significant negative effect on vitamin E content.
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Multirezidual analysis of selected pesticides in barley
Ehrenbergerová, Martina ; Duroňová, Kateřina (referee) ; Mikulíková, Renata (advisor)
Barley is one of the economically important crops. Its production is primarilly used as fodder barley and also in brewery and food industry. Particularly the part of its production intended for malt production must be of high quality. There are some important factors which can influence the quality of the crops, such as harmful organisms – diseases, pests and weed. In order to regulate the occurence of harmful organisms, agricultural measures are taken in the integrated protection system and resistant variants and pesticides are used. The higher the demand on the production quality, the bigger is the volume and the spectrum of pesticides used. The increasing extent of pesticide use also poses a risk for internal production quality and the environment. This fact makes it necessary to monitor unfavourable influences, including the contents of the pesticide residues in barley. This work studies the possibility of multiresidual determination of some selected pesticides in malting barley.
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Analysis of low-molecular proteins in barley by the SDS-PAGE method during malting
Myslivcová, Pavla ; Svoboda, Zdeněk (referee) ; Mikulíková, Renata (advisor)
This diploma thesis deals with the analysis of low molecular weight proteins in barley during malting by SDS-PAGE method. Attention was paid to PR proteins, specifically LTP proteins and thionins, considered to be connected with gushing effect. Barley samples, malt intermediates and malt samples taken in 10 consecutive days to cover the whole malting process were used for the experiment. In total, 5 samplings were used for the analysis. Proteins extracted from the samples were separated by SDS-PAGE using a Tris-tricine buffer system. The protein lines of LTP proteins and thionins were identified in the resulting gels. The relative optical density values of the selected protein bands were obtained to assess the effect of malting on these proteins. A similar pattern of change in the content of mentioned low molecular weight proteins during the malting process was observed. This was confirmed by finding a statistically significant positive correlation between the relative optical density values of LTP proteins and thionins. Furthermore, the relationship between the low molecular weight protein content and the gushing potential and the microbiological contamination of the samples was investigated, but was not confirmed.
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Determination of lipids and fatty acid profile in a barley caryopsis
Cvrková, Jana ; Vítová, Eva (referee) ; Svoboda, Zdeněk (advisor)
The diploma thesis deals with the determination of lipids and fatty acid profile in a barley caryopsis.(Hordeum vulgare). The theoretical part describes the synthesis of fatty acids and their degradation in plant material, secondly, it described the possibilities of lipid extraction and their determination and the possibilities of determination of fatty acids. In the experimental part method of lipid extraction on automated extractor Fex ®IKA and determination of fatty acids by GC-FID were optimized. For analysis of fatty acids two capillary columns SLB-IL 100 and Supelcowax were compared. Twenty varieties of barley from the year 2008 and twenty varieties from the year 2009 were compared based on the content of lipids and the representation of fatty acids in a barley caryopsis. The diploma thesis was realized in the Research Institute of Brewing and Malting, Plc. in Brno.
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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).
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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).
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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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