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Obtaining and complex charaterization of Aronia spp. extracts
Seidlová, Kateřina ; Zemanová, Jana (referee) ; Veselá, Mária (advisor)
Aronia (Aronia melanocarpa) is a berry fruit with distinctive sensory characteristics and health-promoting properties. Polyphenols are the main bioactive compounds found in aronia including natural pigments – anthocyanins. Bioactive compounds are usually obtained from natural materials by extraction, in this work, two methods of extraction were compared – maceration and PHWE. Based on the total phenolic content, maceration was chosen as a more suitable method and then was optimized with statistical model – Design of Experiment. Optimal conditions were set to temperature of 30 °C, extraction agent 50 % ethanol, solid-solvent ratio 10 g per 50 ml and time of extraction for 30 minutes. Extract obtained under these conditions was characterised by total phenolic content – 1441 ± 90 mg/100 g DW, total anthocyanin content 943 ± 8 mg/100 g DW and antioxidation activity by ABTS 24,78 ± 0,09 molTE/g. In total of 25 volatile compounds were indentified in the optimal extract with content > 0,5 %. Major part created aldehydes and esters, with the main compounds being benzaldehyde (32,25 %) and methyl hexanoate (21,37 %).
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Preparation and characterization of Echinacea extracts
Pallová, Jana ; Veselá, Mária (referee) ; Vítová, Eva (advisor)
Echinacea purpurea is a rich source of biologically active compounds, which are attributed to several therapeutic effects. This thesis is focused on the optimization of the extraction process, considered these substances. Maceration was chosen as a type of extraction, due to its simplicity. The Optimal conditions were solid-solvent ratio 1: 5, 40% ethanol, 60 °C, 60 minutes. An extract from the dried flowers of Echinacea purpurea was prepared by this optimized process. The content of total phenolic compounds was set on 365.18 ± 3.51 [mg_GAEl^(-1)] and the antioxidant activity was 507.50 ± 6.89 [mg_TEACl^(-1)]. The percentage of radical scavenging activity ABTS•+ was 95.45 ± 1.30. The antimicrobial activity of the extract was tested against 3 microorganisms – Escherichia coli, Bacillus cereus and Candida glabrata. There was not detected inhibitory effect on the growth of microorganisms. In a total, 39 volatile compounds were identified, and the biggest group were represented sesquiterpenes (70.9%). The obtained results confirm that Echinacea extract has antioxidant activity and contains several interesting aromatic substances, In the future, it can be used as a natural resource of nutritionally and sensory valuable compounds, e.g., into various foods and delicacies.
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Hevlín – place in the landscape
Kubíčková, Karolína ; Veselá, Markéta (referee) ; Foretník, Jan (advisor)
The aim of the thesis is to create a landscape that supports water retention and helps the river Dyje to create a branched, meandering watercourse. The design also deals with the permeability of the territory and the design of wooden objects that respond in function and shape to the created landscape.
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Study of emulsion stability by means of physical-chemical and optical methods
Kuchyňová, Jitka ; Veselá, Mária (referee) ; Zmeškal, Oldřich (advisor)
The diploma thesis deals with the stability determination of model O/W (30/70) emulsions at 25°C. In fact, the time and emulsifier concentration (Tego Care PS) dependences of physical properties (aging) were monitored. In the second part of the work, the influence of conservant on emulsion stabilities were studied. In order to study physical properties of emusions rheometry, differential scanning calorimetry (DSC) and optical microscopy were employed. The rheological measurement provided information on viscosity and viscoelastic modulus. DSC experiments used the repeated freezing/thawing cycles which allowed monitoring of changes in crystallization temperature of water present in emulsions and melting enthalpy of ice formed during the cooling. The optical microscopy was used to examine the change in oil droplet size in the course of emulsion destabilization and phase separation. In this case the image analysis was carried out using program HarFA. The results showed that due to the emulsion creaming, the oil droplets diffuse and aggregate which causes phase separation. Those processes were quickest for the emulsion with lowest emulsifier concentration 0.1 % (destabilization during 51 days) The emulsions with emulsifier concentration about 1.5 and 1.3 % were stable at least for 4 months. The presence of the coemulsifiers increased the elastic modulus and descreased the phase difference due to the network formation. It was shown that for the stability determination is necessary to use conservant due to risk of microbial contamination. DSC experiments allowed to distingush samples prepared under different conditions. Lower rotational speed during emulsion preparation caused the appearance of two melting and crystalization peaks while for higher speed only one peak was observed.
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Hranice – redefinition of urban structure
Varmužová, Adéla ; Veselá, Markéta (referee) ; Foretník, Jan (advisor)
I think of a library in a small town as a social center rather than a closed institution. It should be seen as part of the public space of the city, an open place with a cultural - educational and social life. Apart from the possibility of concentrated individual study, it should also provide space for group work and social gathering of residents. Authors' readings, lectures and workshops are held in such a library. The library environment should be pleasant and suitable for a long stay with plenty of natural light and contact with the exterior. It includes a literary café, a buffet and an open-air reading room. The library in Hranice is designed as a terraced "house" with walking roofs. The building creates a link between the park and the street of 1. Máje. You can walk through the library from the street to park and vice versa, both through the interior of the library and outside on its roof.
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Photocatalytic inactivation of yeast in flow reactor
Lipenská, Michaela ; Drbohlavová, Jana (referee) ; Veselá, Mária (advisor)
This diploma thesis focuses on the photocatalytic effect of titanium dioxide and ultraviolet light. Theoretical part shows the effect of titanium dioxide and aplication in various branches. Antibacterial effect of titanium dioxide iluminated by ultraviolet light was observed in the flow tube reactor on the yeast Hansenula anomala. After adjusting the optimal flow rate experimented with different inicial concentration of yeast cells. To increase desired effect also silver was used in the photocatalytic system. As observed in many previous studies, silver decreases the time needed for killing the microorganisms. The optained date were analysed.
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Bioactive compounds of fennel
Nentvichová, Aneta ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this bachelor thesis is to study the bioactive substances contained in fennel, to determine the content of polyphenols, flavonoids and to investigate the antioxidant and antimicrobial activity in aqueous and ethanol extracts of fennel. The theoretical part discusses the characteristics of fennel, its classification in the system, its use and especially the bioactive substances contained in it. The experimental part is divided into two sections, where the first part focuses on spectrophotometric determination of polyphenols, flavonoids and antioxidant activities. In the second part the antimicrobial effects of prepared extracts of fennel were examined. Two microorganisms Serratia marcescens and Bacillus cereus were exposed to the said extracts. Antioxidant activity and relatively high content of polyphenols and flavonoids were found in the extracts in the first experimental part. The second experimental part proved that the antimicrobial effect of the extracts was very low, in most cases almost negligible. Ethanol extracts showed higher antimicrobial activity, while hot water extracts found to support the growth of Bacillus cereus.
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LABORARTORY BRNO
Smržová, Kristýna ; Veselá, Markéta (referee) ; Kratochvíl, Jan (advisor)
I suggest two buildings, gallery and multifunctional building. For my design solutions was crucial that we find ourselves in a place with very strong traffic and small place. I design primarily the gallery, so I decided to open the block and relieve the gallery building. With the same intention i taper the wall of the main facade to the street fluctuate, thus creating a freer parter. Gallery becomes detached building and operating space around freely. I wanted to reach such an impression that it was a stone house, something quality and stable, so I chose the concrete substructure as well as the exposed material. The construction is monolithic reinforced concrete. The second house is a multifunctional building directly adjacent to the Commercial Bank
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Determination of antimicrobial activity of herbal extracts
Žitková, Barbora ; Veselá, Mária (referee) ; Vítová, Eva (advisor)
The aim of this bachelor thesis was to observe the antimicrobial activity of selected herbal extracts and essential oils against three selected microorganisms, bacteria – Bacillus cereus, Escherichia coli and the yeast Candida glabrata. Two diffusion methods were used to verify and compare the antimicrobial activity, namely the diffusion well and disk method. The theoretical part describes the characteristic of plants from which extracts and oils were made. It also focuses on active substances, vitamins and minerals contained in herbs. Other methods that can be used to determine antimicrobial activity are also mentioned in the work. At the end of the theoretical part the characteristic of the microorganisms used for observation is mentioned. The result of the diffusion well method shows that only eucalypt oil showed antimicrobial activity against all selected microorganisms. It was most effective against Bacillus cereus with an inhibition zone size of 1.73 ± 0.11 cm. The result of the diffusion disk method shows that there are two oils which showed antimicrobial activity against selected microorganisms, namely marrow and eucalypt oil. Nevertheless, the most effective oil was made of mint against Bacillus cereus with an inhibition zone size of 1.57 ± 0.31 cm.
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