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Study some active substances in Czech beer
Pařilová, Kateřina ; Vávrová, Milada (referee) ; Márová, Ivana (advisor)
The aim of this work was to study phenolics and other active compounds in 22 kinds of lager beer and especially to find some differences between Czech beer and beers made in foreign countries. In theoretical part the most useful methods for phenolic and protein analysis are discussed. Further, basic steps of brewery technology are introduced and main beer components with regard to Czech beer specificity are presented. Analysis of total phenolics, total flavonoids, antioxidant activity and most of basic technological characteristics was performed spectrophotometrically. To identification and quantitative analysis of individual phenolics on-line liquid chromatography with photo-diode array (PDA) and mass spectrometry (MS) detection was used. Protein analysis was performed by vertical electrophoresis SDS-PAGE and by Experion microfluidic electrophoresis (BioRad). From the total of 22 samples, 15 Czech beers and 7 beers of foreign marks were enrolled into this study. In these samples levels of brewery characteristics, group antioxidants and individual phenolics were compared. Flask and can beers as well as alcoholic and non-alcoholic beers were compared too. As a model comparative sample the Czech hop of Sládek variety was used. Finally, usefulness of tested parameters to differentiation composition and technology of individual beer samples was evaluated and parameters suitable for Czech beer authenticity analysis were proposed.
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Encapsulation of some enzymes into organic particles
Hazuchová, Eva ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on encapsulation of some enzymes into organic particles. The theoretical part is aimed to enzymes, their general characteristics, structure, activity and use, and to encapsulation techniques. Some methods used for analysis of particles, namely the determination of the distribution of particle size using dynamic light scattering, and determining the stability of the particles by the zeta potential, are described too. The experimental part describes methods of preparing particles, methods of determining the encapsulation efficiency and methods for determining particle size and stability. During the experiment part four types of enzymes were encapsulated, partly by manual preparation and partly by encapsulator. Encapsulation efficiency, size and stability of prepared particles were determined too. The particles were exposed to artificial intestinal, gastric and bile juices, as well as the effect of model foods. Subsequently, their long-term stability was observed.
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Analysis of phenolics in different kinds of coffee
Jašková, Martina ; Halienová, Andrea (referee) ; Márová, Ivana (advisor)
The aim of this bachelor thesis was examining the quantity of biologically significant substances in selected types of roasted ground coffee, instant coffee and coffee extract. The particular kinds of coffee differed in technological processing, degree of roasting and composition. In the practical part total phenolics and flavonoids by using spectrophotometry methods. The total antioxidant activity in the individual coffee extracts was determined by ABTS method. Qualitative and quantitative analysis of some individual antioxidants and caffeine was performed using RP-HLPC with spectrophotometric detection. As a part of the work sensory analysis of all coffee samples was realized and consumer questionnaires were completed.
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Analysis of active substances in honey
Jelénková, Zuzana ; Kubešová,, Jitka (referee) ; Márová, Ivana (advisor)
This diploma thesis was focused on biologically active compounds determination. 26 samples of honey, one sample of propolis and one sample of royal jelly were analyzed. Honey were harvested in year 2006 and 2007 and bought in retail chain, special shops and directly from bee-keeper. Samples were analyzed by titration, spectrofotometry, LC/MS and RP-HPLC methods. The study was focused on analysis of antioxidants. Followed groups of antioxidants were determined: flavonoids, catechins, carotenoids, vitamins E, C, A. Authenticity of quality was determined by hydroxymethylfurfural analysis. Average values of total antioxidant capacity ranged (12.75-137.49) mmol .100 g-1. Average values of total phenolic ranged (8.51-61.34) mg .100 g-1 and average values of total flavonoids ranged (0.75-6.04) mg .100 g-1. Honey samples contained (41.83-585.10) g .100 g-1 of rutin, (9.30-313.40) g .100 g-1 of myricetin, (6.5-171.90) g .100 g-1 of luteolin, (3.19-436.37) g .100 g-1 of quercetin, (2.10-242.66) g .100 g-1 of apigenin, (0.15-105.12) g .100 g-1 of caempferol and (0.07-17.52) mg .100 g-1 of naringenin. From group of catechins there were measured (5.98-310) g .100 g-1 of catechin, (17.77-486.29) g .100 g-1 of epicatechin, (0.18-64.90) g .100 g-1 of catechin gallate and (0.59-140.56) g .100 g-1 of epicatechin gallate. From lipophilic compounds the most abundant in honey samples was tocopherol, its value ranged (29.20-8531.17) g .100 g-1. Content of ascorbic acid ranged (0.65-4.65) mg .100 g-1. Content of hydroxymethyl.furfural. ranged (0.26-4.06) mg .100 g-1. By LC/MS method luteolin, naringenin, protocatechin acid, coffee acid and p-cumaric acid in honeydew were detected and, furthermore, kyanidin and pinocembrin in floral honey were found. Mono-floral honey contained biologically active compounds the most, imperceptibly less contained multi-floral honey and honeydew honey. Acacia honey contained the lowest amount of biologically active compounds.
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Diffusion properties of oppositely charged organic molecules in solutions of hydrophilic polyelectrolyte
Rýcová, Eva ; Márová, Ivana (referee) ; Mravec, Filip (advisor)
This work is focused on physical interactions of negatively charged polymers with small ionogenic fluorescent molecules. Trying to verify the presence of these interactions using fluorescence correlation spectroscopy (FCS) and provides a comprehensive view of the problem. The aim of this work is to observe the effect of concentration on the diffusion properties. P/D ratio, where P represents number of polymer binding sites and D number of dye binding sites, was chosen for this issue. Hyaluronate, sodium chondroitin sulfate and sodium polystyrene sulfonace were used as polymers and Acridine Orange, and Rhodamine 6G were chosen as fluorescent probes. The reason why this experiment uses these probes, was the assumption, that the positive charge occuring on the fluorescent probe will lead to the electrostatic interaction with the negatively charged polymer. As a result, the bond between acridine orange and polyelectrolyte was not clearly demonstrated, but the interaction with Rhodamine 6G have been proved.
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Production of Selected Yeast Metabolites Applicable to Food Supplements
Němcová, Andrea ; Čertík, Milan (referee) ; Vávrová, Milada (referee) ; Márová, Ivana (advisor)
Carotenoids are naturally occurring pigments of plants also produced in many bacteria, and fungi. They represent one of the widest group of natural antioxidants with significant biological effects and numerous of industrial applications. There is an increased interest in carotenoids as natural antioxidants for their ability to reduce chronic diseases, various pathological stages and aging. The area of their application concerns mainly food industry; however, they are used in chemical, pharmaceutical, and cosmetics industry as well. One possibility is study of potential of red yeasts that are able to convert various substrates into carotenoid pigments. In presented thesis carotenogenic yeast belonging to the genus Rhodotorula, Sporobolomyces and Cystofilobasidium were tested for ability to use of selected waste substrates and also random mutagenesis in order to increase the production of biomass and specific metabolites – carotenoids and other lipid-soluble substances. As alternative nutrient sources derived from waste substrates from agricultural and food production (rapeseed substrate, rice, wheat, apple fiber, pasta and lignocellusic materials) were tested. To selected production media extracellular hydrolytic enzymes or commercial enzymes degrading polysaccharide were added. All tested red yeast strains were able to utilize these substrates as the only carbon source and simultaneous produce carotenoid enriched biomass. In this work, characterization of carotenogenic yeast using molecular techniques was studied. For this usage, interspecific variables of strongly conserved sequences of genomic DNA, especially rDNA D1/D2 large ribosomal subunit and ITS1 and 5,8-ITS2 rDNA regions were amplified. These sequences were subjected analysed by DGGE method to compare differences of carotenogenic yeasts. Isolation procedure of the intact DNA were optimized for caryotypic yeast characterization by pulsed field gel electrophoresis (PFGE). The karyotype of tested yeasts contain visible differences between yeast species and genera.
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Analysis of biologically active substances in some cereal products
Valentová, Radka ; Starečková, Terezie (referee) ; Márová, Ivana (advisor)
Presented bachelor thesis is focused on study of biologically active substances in cereal products. In theoretical part over view of cereal active substances, predominantly phenolic compounds were introduced. In practical part 15 kinds of cereal products were analyzed. In these materials some group parameters - total phenolics, total flavonoids and total antioxidant activity were measured by spectrophotometry. RP-HPLC/UV-VIS method was performed for analysis of selected individual flavonids. The highest content of phenolic compounds was measured in cereals containing fruits (raspberries, blueberries, tropical and red fruit), cacao, crusty fruits (hazel nuts, sunflower seeds) and buckwheat. All cereal products contain catechine, epicatechine, catechin gallate, epicatechin gallate, chlorogenic and ferulic acid. As a part of bachelor thesis simple sensory analysis was performed and consumer questionnaires were evaluated.
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Development of organic UV filtres based on natural extracts
Káčeríková, Martina ; Kovalčík, Adriána (referee) ; Márová, Ivana (advisor)
This diploma thesis is focused on the development of organic UV filters. Organic UV filters were extracted from natural resources and encapsulated into nanomaterial-like delivery systems such as liposomes and nanofibres. SPF of particular extracts and carriers with encapsulated extracts were measured. All of the prepared extracts as well as carriers were characterised for their content of natural substances like phenolic compounds and their antioxidant acitvity, stability, cytotoxicity, micriobial acitivity and their safety were studied too. All of the prepared materials were evaluated as suitable for use in comestic industry. However, in a future, it would be appropriate to add to the study other experimental methods to increase the active substances and at the same time increase the SPF protection factor.
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Advanced materials for organic electronics and bioelectronics
Šudomová, Lucie ; Márová, Ivana (referee) ; Weiter, Martin (advisor)
This bachelor thesis focuses on the characterization of organic materials with semiconductor properties in terms of their potential use in bioelectornic applications. The theoretical part is summarizing the basic characteristics of organic materials for organic electronics and bioelectronic. There are mentioned basic structures and general properties of relevant substances. This part of the thesis also describes the basic principles of devices for bioelectronic applications and its use. Practical part includes preparation of thin films of two types substances: on the basis of low-molecular organic substances (6,13-bis(triisopropylsilylethynyl) pentacene and diketopyrrolopyrrole) and another based on polymers (Poly (3-hexylthiophene-2,5-diyl) and Poly (3,4-ethylenedioxythiophene): poly (styrene sulfonic acid) and). The first part of the experiment is focused on the characterization of the properties of used substances. The second part examines microbial biocompatibility
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Biotechnological valorization of some food wastes by yeasts
Majdloch, Robert ; Bendová, Agáta (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with biotechnological valorisation of waste substrates, namely waste fat, whey and feathers using carotenogenic yeast. Waste substrates serve as alternative source of nutrients for subsequent cultivation, thanks to this, their utilization and subsequent production of carotenoids, ergosterol, coenzyme Q and lipids occurs. The theoretical part contains the information of selected strains of carotenogenic yeast, such as physiological and growth properties. Their metabolic processes are described together with produced substances. The analytical methods for the determination of substances are described as well. The experimental part focuses on the solution of flask and bioreactor cultivations of four selected strains (Rhodotorula kratochvilovae, Rhodotorula mucilaginosa, Cystofilobasidium macerans a Sporidiobolus pararoseus) on glucose, glycerol and waste substrate at different C/N ratios (13, 25, 50 and 100). Furthermore, individual procedures of waste substrate processing, procedures solving isolation and determination of selected carotenoid substances, which were analysed by HPLC/DAD. Lipid content and their percentage amount were determined by GC/FID. The results of flask and bioreactor cultivations show that the strains have different production at individual C/N ratios. Rhodotorula mucilaginosa strain was selected as the best producer of carotenoids and ergosterol. The highest increases in biomass were achieved by Rhodotorula kratochvilovae strain. Lipid production was the best in the Sporidiobolus pararoseus strain.
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