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Aronia as a raw material for cosmetic production
Palkovská, Kateřina ; Sýkora, Michal (referee) ; Zemanová, Jana (advisor)
This bachelor thesis deals with extraction of polyphenols from fruits and leaves of aronia and consequent use of obtained extract in cosmetic production. In the theoretical part are information about the origin of the aronia, the botanical characteristics of Aronia Melanocarpa and about its utilization. Furthermore, the chemical composition of the plant material of the aronia is described, which is also common for fruits. At the end of the theoretical part are described extraction and separation techniques, methods of determination of total polyphenolic compounds and brief characteristics of the material safety data sheet. The experimental part describes the optimization of the prepared extract so that the extract contains as many polyphenolic compounds as possible. 50% ethanol at room temperature was shown to be optimal for leaf and fruit extraction, and the maceration time was found to have a significant effect on the polyphenolic compounds obtained. For the obtained optimized macerate, some chemical and physical properties such as pH, density, refractive index were determined for the purpose of producing a material safety data sheet and product specification. At the end of the experimental part were prepared cosmetic products with the addition of macerate from crushed aronia fruits.
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Implementation of modular arithmetic in FPGAs and ASICs
Sýkora, Michal ; Bohrn, Marek (referee) ; Dvořák, Vojtěch (advisor)
This thesis is focused on analysis, design and implementation of modular arithmetic in FPGAs and ASICs. Its main objective is to create a C++/SystemC library, that contains synthesizable functions for operations with Montgomery reduction in modular arithmetic. Results of the implementation of Montgomery reduction are compared with results of classic algorithms for modular arithmetic.
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Characterization of nut oils
Coufalová, Dominika ; Sýkora, Michal (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the characterization of selected nut oils, almond and pistachio virgin oils. The teoretical part concentrates on the description of nut fruits, the characterization of aroma-active compounds, fatty acids and their content in the nut oils. After that, the fatty characteristics, which determines the oil quality, and instrumental methods selected for individual assignment are described. In the experimental part there were 42 volatile compounds identified in the nut oils by the headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry, 35 were found in almond oil and 24 were found in pistachio oil. Free and bound fatty acids were converted into methyl esters using acid-catalysed esterification with boron trifluoride-methanol solution as a catalyst and then they were determined by gas chromatography with flame ionization detection. There were 12 fatty acids identified in almond oil and 14 fatty acids in pistachio oil. Oleic acid and linoleic acid predominated in both samples. The quality and properties of nut oils were valued by determining the fatty characteristics (acid value, saponification value, ester value, iodine value by Hanus method and peroxid value). The increased value of peroxide value was found in both oils which correlates with the trait and storage time of samples.
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Assessment of fatty acids in processed cheese
Mitra, Michal ; Sýkora, Michal (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with determination of fatty acids in samples of processed cheeses made at Tomas Bata University in Zlín. In the theoretical part, lipids and fatty acids are characterized. Subsequently, the issue of production, distribution and composition of natural and processed cheeses is discussed. The conclusion of the theoretical part is focused on the assessment of fatty acids, i.e. their extraction and the determination by gas chromatography. In the experimental part, the fatty acid content of the seven samples of processed cheese was compared on the basis of different temperatures and the time of their production. The ČSN EN ISO 1735 method was used for extraction of fat. The method with methanolic potassium hydroxide solution was used for esterification. The determination of fatty acid methyl esters alone was accomplished by gas chromatography with a flame ionization detector. Based on the comparison with the standards, 17 fatty acids were identified in the samples.
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Design of tool magazine for CNC mill
Sýkora, Michal ; Tůma, Zdeněk (referee) ; Tůma, Jiří (advisor)
This bachelor thesis deals with automatic tools change on machine-tools. In the thesis, there is a research from the issue of ATC on machine-tools, focused on individual types of tool magazines. Then the necessary construction calculations are made there. Based on the calculations, the disk-type magazine is designed in 3D software. Assembly drawings and production drawings of three components are also part of the bachelor thesis.
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The optimization and validation of the method for assessment of free fatty acids
Sýkora, Michal ; Diviš, Pavel (referee) ; Vítová, Eva (advisor)
This master thesis deals with the development of method for free fatty acids determination in natural and processed cheese. In the theoretical part the possibilities of extraction, fractionation and determination of lipid fractions, characterization of fatty acids and various methods of their determination are described, as well as determination of free fatty acids. The main scope of the experimental section is optimization and validation of the selected method for determination of free fatty acids in various cheese matrices. For extraction of lipids from the sample the method with the mixture of diethylether and petrolether according to ČSN EN ISO 1735 was selected. Thin-layer chromatography and solid phase extraction were tested and compared for separation of free fatty acids. The method according to ČSN EN ISO 5509, using methanol solution of bortrifluoride, was applied for esterification. Fatty acid methyl esters were determined by gas chromatography with flame-ionization detection.
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XML Dictionary Tagging
Sýkora, Michal ; Šilhavá, Jana (referee) ; Smrž, Pavel (advisor)
This bachelor thesis describes the management of dictionary data in XML format, especially the family of XML standards and their use in work with dictionaries. In addition, the system for their storage, specifically DEB II.The practical part show a dictionaries transfer to the LMF standard, installation and launching DEB II. In conclusion is discussion about the advantages and disadvantages of the system.
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Assessment of aroma active compounds in selected type of cheese
Dostálková, Andrea ; Sýkora, Michal (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the aroma active compounds of Emmental and Moravský bochník types of cheeses, i.e. natural hard cheese with high heat curd. In the theoretical part these cheeses are characterized, their chemical composition is described as well as individual steps of their manufacturing process. After that a literature search focused on aroma active substances is made and the following methods are described: solid phase microextraction for their isolation and gas chromatography with mass spectrometry for detection. In the experimental part the selected SPME-GC-MS method is used to identify volatile aroma active compounds in cheeses with high heat curd bought on the market and samples of model cheeses manufactured at Tomas Bata University in Zlín with the use of various ratios of added dairy cultures. The differences among samples were found in the number and types of volatile compounds. A total of 129 compounds were identified in samples; of those 35 alcohols, 9 aldehydes, 24 ketones, 16 carboxylic acids, 23 esters, 1 ether, 16 hydrocarbons, 2 sulphurous and 3 nitrogenous compounds.
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Automatic Image Labelling
Sýkora, Michal ; Beran, Vítězslav (referee) ; Hradiš, Michal (advisor)
This work focuses on automatic classification of images into semantic classes based on their contentc, especially in using SVM classifiers. The main objective of this work is to improve classification accuracy on large datasets. Both linear and nonlinear SVM classifiers are considered. In addition, the possibility of transforming features by Restricted Boltzmann Machines and using linear SVM is explored as well. All these approaches are compared in terms of accuracy, computational demands, resource utilization, and possibilities for future research.
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Changes of sensory active substances during ripening of selected type of natural cheese
Sýkora, Michal ; Buňková, Leona (referee) ; Gregor,, Tomáš (referee) ; Buňka, František (advisor)
The presented dissertation is a study focused on the characterization of sensory quality, especially the flavour of model samples of natural cheeses. Attention is aimed to the composition and content of volatile (sensory active) substances as important markers of flavour and free/bound fatty acids as their precursors. The headspace solid phase microextraction in conjunction with gas chromatography with mass spectrometry was used to determine volatiles. For the determination of fatty acids, the lipids were isolated from the sample with a solvent mixture of diethyl ether and petroleum ether, followed by esterification using a methanolic solution of boron trifluoride as a catalyst and final analysis by gas chromatography with flame ionization detection. The experimental part was divided into two experiments; in experiment I, Moravský bochník type cheeses (45 % fat in dry matter., 60 % dry matter) were analysed, in experiment II, Edam type cheeses (45 % fat in dry matter, 50 % dry matter). Model samples of cheeses were made at Tomas Bata University in Zlín. For all samples, a classical mesophilic culture containing Lactococcus spp. and Leuconostoc spp. was used, this was always supplemented with a suitable monoculture of thermophilic bacteria; in the case of Moravský bochník cultures of Streptococcus thermophilus and Lactobacillus helveticus and in the case of Edam cheeses Lactobacillus casei and Lactobacillus plantarum. The essence of both experiments was to assess the influence of the used microbial cultures on the above-mentioned parameters, at the same time their changes during the ripening of the cheeses were monitored. The results showed that the addition of thermophilic cultures, as well as the maturation process did not affect the number of fatty acids or volatiles, but significant differences were found in their content. The content of bound fatty acids decreased during cheese ripening due to ongoing lipolytic changes while increasing the content of free fatty acids and their subsequent degradation to volatile substances, which ultimately contribute to the taste and aroma of the cheese. Ketones and acids were the most quantitatively present in all samples. During maturation, contrary to expectations, the content of identified volatiles also decreased. The addition of the thermophilic cultures didn’t have a clear effect and varied depending on the maturation phase. In the first phase, although they showed more pronounced lipolytic activity, the subsequent metabolic processes - the breakdown of free fatty acids into volatile substances, compensated for these differences. These results confirm a significant share of the basic mesophilic culture in the formation of volatile substances, in particular the flavour of cheeses.
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