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Disposable sensor of ammonium for intelligent packaging
Nentvichová, Aneta ; Kořínková, Radka (referee) ; Veselá, Mária (advisor)
This diploma thesis is focused on the problematic of the smart packaging and deals with the preparation of disposable ammonia sensors/indicators and the subsequent color measurement of prepared sensors/indicators using the CIE L* a* b* color space. The theoretical part of the diploma thesis focuses on active and intelligent packaging, using ammonia sensors/indicators. The emphasis is placed on the main components of the sensor/indicator, i.e., chitosan as a polymer and curcumin as a dye. The theoretical part also includes the problematic of meat degradation, which plays a very important role in this thesis. The experimental part was divided into two parts. The first part was to prepare layers that will respond in different colors based on the concentrations of ammonia. Prepared layers were sensitive to ammonia across all concentrations, and based on this result, ascorbic acid was applied to compositions to achieve a calibration retention of the selected amount of ammonia. The second minor part of the experiment was the application of selected layers to packages with real meat.
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Comparison of aroma profile of fruit distillates
Koubek, Miroslav ; Veselá, Mária (referee) ; Vítová, Eva (advisor)
This master thesis deals with the assessment of aroma active compounds in fruit spirits. In the theoretical part the production technology of fruit spirits from raw materials to final product is described. Furthermore, aroma active substances are characterized, and the method for their determination by solid phase microextraction and gas chromatography with mass spectrometry is described. The aim of the experimental part was the identification of volatile substances in different kinds of fruit spirits. Aromatic compounds were identified by the SPME-GC-MS. Domestic fruit spirits obtained from private growers were used as model samples. The differences in the number and type of volatile compounds were found between the samples. Overall 53 volatile compounds were identified. These were composed of 25 esters, 9 alcohols, 5 aldehydes, 4 alkenes, 2 ketones, 1 carboxylic acid and 7 other compounds.
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Study of bioactive compounds of fennel
Mierna, Jana ; Skoumalová, Petra (referee) ; Veselá, Mária (advisor)
The master´s thesis is focused on the study of biologically active compounds of fennel. The theoretical part describes basic characteristics of fennel and its chemical composition, further specifies plant´s biological active substances and antioxidants, also describes extraction techniques for obtaining these bioactive compounds, methods of their determination and verification of antimicrobial effect. In the experimental part were spectrophotometrically determined contents of polyphenols and flavonoids in the prepared extracts of fennel tea, whole and crush spice. On the basis of extraction curves, antioxidant activity and potential antimicrobial activity against the selected microorganisms Bacillus subtilis, Bacillus cereus, Serratia marcescens a Micrococcus luteus was determined in the samples with the highest values of the given bioactive substances. Among the all monitored extracts, the inhibitory effect was showed only by an aqueous extract of the fennel tea against the bacterial strain of Micrococcus luteus.
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Smart food polymer layers
Valíková, Michaela ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
Smart packaging represents a group of packaging with great potential when used in the food industry. Active packaging can have a positive effect on the condition of stored food and smart packaging can inform consumers about the condition of stored food. In the theoretical part, a search was made on the topic of packaging in the food industry, with emphasis on active and intelligent packaging, including the legislative framework. The substances from which smart packaging is made have been described. In the experimental part, partially water¬insoluble polymer layers were prepared from gelatin, glycerol, crosslinking agent and anthocyanin extract. Glutaraldehyde or tannic acid was used as a crosslinking agent. Anthocyanins were obtained by extraction from red cabbage. The total concentration of anthocyanins in the extract was determined by the difference method. For prepared layers, their water solubility was measured and the colour response to the pH environment was evaluated spectrophotometrically. The stability of the layers over time was also monitored. It was found that the prepared layers are able respond to changes in pH.
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Impact of elevated carbon dioxide concentration and nitrogen fertilization on protein content of glutenin fraction in winter wheat
Veselá, Markéta ; Vespalcová, Milena (referee) ; Hrstka, Miroslav (advisor)
This bachelor thesis studies the impact of elevated carbon dioxide concentration in the atmosphere and nitrogen nutrition on protein kontent in winter wheat (Triticum aestivum) var. Bohemia. Glutenin proteins were separated by SDS-PAGE method and protein quantification was performed by computer densitometry. It was proved that the nitrogen fertilization has a great influence on the amount of glutenin proteins, which increased in all samples. Effect of elevated CO2 concentrationis not nearly as significant, however certain differences can be seen. Samples of wheat grown under conditions of reduced UV radiation, and samples of wheat grown under natural conditions did not show great differences in the content of glutenins.
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HOUSE ON THE FOOTHILL - TOWN HOUSE IN THE HISTORICAL CENTRE
Veselá, Marie ; Rudiš, Viktor (referee) ; Oplatek, Jiří (advisor)
Potential sites lies not only in its location but also the dominant position it holds to their surroundings. Undeveloped plot represents a "node" or "island" ... loosening strictly linear character Bakery. It is a place which brings together three disparate streams - Classical serious at the running part of Mendel Square, dramatically quarreling upper section flowing into the area from Hus class and insignificant Anenská that, if there "just got lost." All "three" street, however, are closely connected with the plot and the transformation of space clearly indicates their transformation. A distinctive feature of the property is its visual exposure of looking from Mendel Square, the plot creates a "picture" to which the pawn closer. This image should be interesting, changing to attract one's attention for more than just one or two seconds. The image should not least communicate - what is happening on the ground, what links are individual objects ... a landmark and should, for use by infantrymen use. It should also not be attractive from a distance - when one zooms in close proximity, should be surprised by the discovery of something new, something that was not noticeable from a distance, it should be attention to detail, or idea that can be seen only at close contact.
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Price of Construction and Possibilities of Supplier
Veselá, Michaela ; Vítková, Eva (referee) ; Puchýř, Bohumil (advisor)
The aim of this thesis is to describe the possibilities contractor in determining the price at possible changes during the process of construction supplies. You need to have a set price of construction work, which is a necessary part of the work contract. It is good to know the rights and obligations of the parties in the construction. In the practical part, the work deals with the possibility of fixing prices as well by the contractor under the contract for work.
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Microbial contamination packaging glass
Bělohoubková, Tereza ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
The bachelor thesis contemplates the formation of microbial contamination during production of glass packaging used in food industry. The theoretical part defines the word packaging, its function and legislation of glass packaging. Glass packaging production is described as well as arising risks of potential microbial contamination. Unacceptable microorganisms with ability to live on the surface of glass packaging and possible determination of the microorganisms are characterized in the thesis. In the practical part swabs of produced glass packaging were analyzed by ATP bioluminescence and pH of the inner glass surface was determined to assess species of microorganisms able to live on glass surface. Conclusion of the thesis discusses establishments to lower the risk of microbial contamination.
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Study of natural substances of ginger
Dobiáš, Vojtěch ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this study was to determine the quantity of natural substances in ginger. Extracts from organic ginger tea and ginger rhizome were prepared using three different solvents. Antioxidant activity and the content of polyphenols and flavonoids were determined spectrophotometrically. Effects on bacterial growth of the extracts were studied against bacteria Bacillus cereus and Serratia marcescens by agar well diffusion assay. The obtained data showed, that there is a significant amount of difference between the contents of studied compounds in the two extract samples. The highest amount of polyphenols was found in ginger tea with concentration of 0,481 mgml-1, compared to 0,078 mgml-1 found in the ginger rhizome. The tea showed a greater antioxidant activity than the rhizome. Bacterial growth was slightly inhibited only by water extracts of the tea and this was only observed against Bacillus cereus.
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Study of antimicrobial substances of ginger
Ciburová, Alena ; Skoumalová, Petra (referee) ; Veselá, Mária (advisor)
For thousands of years ginger rhizomes are used in traditional Chinese medicine. Because of his significant pungent flavour is commonly used in foods and beverages all over the world. Nowadays many of the beneficial pharmacological positive effects of ginger rhizomes are identified. Their occurrence is due to the high concentration of bioactive compounds. This thesis is focused on analysing of occurrence of bioactive compounds such as polyphenols and flavonoids and their influence on antioxidation and antimicrobial properties of samples of fresh and dried ginger. The results show that for extraction of bioactive compounds in different ginger samples is more suitable to use different types of extraction solvents. The highest antioxidation activity was measured for macerate of 100% bio ginger tea from Sonnentor company in 96% ethanol. Antimicrobial properties were showed only for 100% bio ginger tea against gram-positive bacteria Microccocus luteus.
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