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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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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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Meziplodiny a zaplevelení obilnin
Pluschková, Zuzana
The aim of this master’s thesis was to determine the types of weeds in intercrops and subsequent cereals, to evaluate changesin weeding and to estimate the long-term effects of intercrops on cereal weeding. The weeding rate was evaluated using a numerical method. In the company Hoštická a. s., weeding was observed in various mixtures of intercrops and subsequently cultivated spring barley and maize. In a field experiment carried out at the experiment station Ivanovice na Hané weeding was observed in a barley monoculture after a sown intercrop and after skimming. The results were processed using statistical methods. Weed species were also divided according to different criteria (according to biological properties, according to origin, according to invasive status and according to harmfulness). The results show that monoculture of barley can increase the species representation of weeds. In the long term, intercrops can suppress some types of weeds. Intercrops allow the sprouts of the previous crop to emerge and prevent weeding of subsequent crops. As the diversity of intercrops increases, the list of ecosystem services expands.
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Detekce napadení ječmene listovými chorobami pomocí infračerveného termálního zobrazování, zobazovací fluorescence chlorofylu, UV-stínění fluorescence chlorofylu a hyperspekrálního zobrazování
Holzmannová, Kateřina
The aim of the thesis was, in the theoretical part, to summarize basic information about barley, its use and the leaf diseases that occur most often on barley, and also to summarize the basics of imaging methods potentially useful for the detection of diseases on plant leaves, namely chlorophyll fluorescence imaging, chlorophyll fluorescence UV shielding , hyperspectral imaging and infrared thermal imaging. The aim of the work was to evaluate the potential of individual sensor methods from the point of view of their ability to detect the resistance of spring barley genotypes to powdery mildew based on the experiment carried out with the inoculation of spring barley with grass powdery mildew (Blumeria graminis f. sp. hordei). In the practical part, selected sensor methods are compared within the experiment with 6 lines of spring barley (line of the Pallas variety) differing only in the presence of different genes for resistance to powdery mildew. These lines were chosen to represent a wide range of reaction types in response to infection with avirulent powdery mildew pathotypes, as reaction type can be reflected in the response measured using these indirect methods. Based on the correlation analysis performed for individual parameters measured using tested indirect sensor methods with the values of the light-saturated CO2 assimilation rate, it was possible to state that within each group of methods there is a parameter showing a high ability to predict the plant's response and thus resistance to powdery mildew. It is a chlorophyll index, based on the principle of measuring the infrared and red transmittance of the leaf, the difference between the leaf temperature and the air temperature determined using a thermal camera, the fluorescence decrease ratio - vitality index (Rfd), and finally also the ZM spectral index. In addition to the temperature difference, the values of the Pearson correlation coefficient reach the level of 0.74, which means that it is a highly evident relationship, and the adjusted R2 values are above 0.55, which means that the reliability of the prediction is higher than 55%.
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Vliv technologického postupu na kvalitu sladové whisky
Havlát, Petr
This thesis discusses the specifications of Scotch malt whisky and Irish malt whiskey. It also focuses on various technological aspects of malt whiskey. Specifically malt production, technological possibilities of preparing malt mash, technological influence of fermented malt mash, conditions and processes during maturation and analyzing samples from 100 years old malt whiskey found at the South Pole. The practical part includes the production of malt from the Malz variety of malting barley, from which samples of distillates were subsequently produced under different conditions of sweet mash fermentation and matured for 12 months in laboratory conditions. The distillate samples were mixed according to the type of preparation of the fermented malt mash and diluted to 36 %, 40 %, 44 % and 48 % alcohol by volume. The alcoholic strength varied according to the amount of distillers' yeast added and the length of fermentation. During the practical part, several methods were used to determine the moisture of malting barley, and the starch content in malting barley. Density, alcohol concentration and real alcohol yield were determined psychometrically. Individual samples of the whiskey were GC analyzed after 12 months, revealing a concentration of higher alcohols and several different esters. The CG values were then statistically compared with sensory analysis results which were also statistically evaluated and discussed. The aim of this work was to verify the influence of different technological procedures in the preparation of ripe mash. Apart from dilution, all other technological processes remained the same. Four samples of different alcoholic strengths were created and analysed, one year apart, for the concentration of sensory compounds that carry both positive and negative character in the whisky. The physico-chemical analysis was to be compared with the sensory analysis. The samples were malted in the school's micro malt for pilsner malt. The best sensorial-rated whiskey sample was 44 % alcohol by volume, but this was not statistically confirmed.
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Využití detekce specifických alel genů VRN a PPD pro hodnocení ranosti ječmene
Kárníková, Barbora
This bachelor thesis focuses on the issue of the relation between the presence of specific alleles of genes PPD-H1 and VRN-H1 and the earliness of barley. The evaluation was carried out in a set of recombinant inbred lines (RIL) resulting from reciprocal cross of the semi-late spring barley variety Malz with the spring variety Tadmor, which has a short vernalization requirement and has an early to very early character under certain conditions. First part of the work done was an execution of a field trial and continuous monitoring of its state in rela-tion to phenological development, habitus type and health. The second part consisted of an in-laboratory analysis of the presence of alleles related to vernalization and photoperiodism. The occurrence of PPD-H1 and VRN-H1 alleles, which influence the nature of response to photoperiod requirement fulfilment and also the fulfilment of vernalization requirement, was studied within a set of chosen contrasting lines of generation F10. Relation of these alleles to habitus type, thousand kernel weight (TKW) and the content of nitrogen derived substances was also analysed. The results indicate that within the given genetic background, presence of the dominant allele of the PPD-H1 gene which is passed onto the lines by the Tadmor parental variety, had the most impact on earliness. Within the set of 26 chosen evaluated lines, only one did not exhibit the expected earliness typical for the type of PPD-H1 allele that was present in it’s genome. A statistically conclusive relationship between earliness, habitus type and thousand kernel weight (TKW) was revealed in the results of the evaluation of the relation of earliness to specified morphological and quality-related kernel traits. Relation between earliness and the content of nitrogen derived substances was not statistically conclusive.
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Physiological, structural, and biochemical leaf traits of selected Poaceae species involved in oxidative stress protection and acclimation to different light conditions
Hunt, Lena Macrie ; Albrechtová, Jana (advisor) ; Lux, Alexander (referee) ; Šantrůček, Jiří (referee)
This thesis examines physiological, structural, and biochemical leaf traits in grasses (Poaceae family) and how they contribute to oxidative stress protection. Light is a major factor contributing both to oxidative stress in plants and the induction of protective mechanisms at the leaf level. The agriculturally important species barley (Hordeum vulgare) was used to investigate responses to varying irradiance and atmospheric CO2 levels. Barley was further used as a model organism to study the influence of different spectral qualities on oxidative protective mechanisms, particularly phenolic compound induction. This thesis also examines the protective leaf functional traits of wild grass species (Nardus stricta, Calamagrostis villosa, Molinia caerulea, and Deschampsia cespitosa) in a high-irradiance arctic-alpine tundra grassland. Phenolic compounds are important protective secondary metabolites in plants that protect against oxidative stress from high irradiance. This thesis evaluates phenolic compounds and their contributions to plant stress tolerance and introduces a novel method of quantifying the histochemical detection of phenolics in leaf cross-sections. Key results indicate that light quantity and quality play major influential roles in the accumulation of phenolic compounds. High irradiance...
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Lipid and fatty acid content depending on the barley variety
Havlíková, Michaela ; Pernica,, Marek (referee) ; Svoboda, Zdeněk (advisor)
The bachelor thesis deals with the evaluation of the influence of barley variety on lipid content and fatty acid profile. Samples of barley and malt from the 2022 harvest, seven varieties recommended by Research Institute of Brewing and Malting, Plc. for the production of beer with the protected geographical indication ,,České pivo“, were analysed. The theoretical part of the thesis characterizes lipids and fatty acids, describes their occurrence and importance in barley grain, describes the changes associated with them during the technology of malt and beer production and how these changes can affect the final quality of beer. The possibilities for the determination of lipids and fatty acids are given and attention is paid to the determination of the fatty acid profile by using the method of gas chromatography. In the experimental part, lipids were extracted from barley grains and malt by fluidized bed extraction method using the fexIKA® dive-in control extractor. The extracted lipids were transesterified into methyl esters of the corresponding fatty acids, which were analysed by gas chromatography with flame ionization detection on a SLB-IL 100 capillary column. In both barley and malt were identified eight fatty acids as their methyl esters. The predominant fatty acid was linoleic acid. Reduction of total lipid content and change in fatty acid profile due to the malting process were observed.
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Využití vybraných komponentů rostlinného původu ve výživě ryb
Zugárková, Iveta
The main aim of this Bachelor´s thesis was to create a literary review on the use of selected plant components in fish nutrition. Part of the review contains data on fish bre-eding and nutrition, nutritional requirements regarding the nutrients and customization of fish food. The second part of the Bachelor´s thesis presents a draft on the methodo-logy of a feeding test. Both scaled and mirror forms of common carp (Cyprinus carpio L.) will be used in this test and fed different crops: feeding and low-phosphate wheat, feeding and pearl barley. The corps will be processed into granule to make the food intake and utilization easier. The test will star in May 2016 and be carried out in the recirculation system of the aquarium room at the Department of fishery and hydrobiolo-gy of the Mendel University in Brno. The aims of the test is to evaluate the production effectiveness of used crops, including their influence on the chemical composition of fish tissues and selected parameters of internal environment of fish bodies. The tested crop species were chosen based on the data on the influence of various crops on the phosphorus level reductions in fishponds. Because the plant food for carp represents the most expensive part of carp breeding, there is ongoing research for finding economically and nutritionally suitable food.
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