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Assessment of aroma active compounds in cultivars of apples
Mahdalová, Martina ; Trachtová, Štěpánka (referee) ; Vítová, Eva (advisor)
The aim of this master‘s thesis was to determine the aroma active compounds and monitor the sensory quality of apples. The theoretical part deals with the description, composition and properties of apples, information about the aroma compounds, their determination and possibilities for sensory evaluation of apples is also given. The gas chromatography method combined with the solid-phase microextraction, utilized for the specification of aroma compounds, is described. In the experimental part, the SPME-GC-FID method was applied on selected cultivars of apples specially cultivated against apple scab (Venturia inaequalis), i.e. 24 genotypes and Golden Delicious as the control variety. In total 60 various aroma compounds were identified, 22 alcohols, 12 aldehydes, 11 ketones, 10 esters and 5 organic acids. The number and concentration of compounds identified differed according to the cultivars. Sensory analysis was performed using category ordinal scales and the profile test.
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Analysis of micloflora in cheeses using DGGE
Čakajdová, Martina ; Rittich, Bohuslav (referee) ; Trachtová, Štěpánka (advisor)
Molecular biological methods are fast and efficient tool for the identification of microorganisms in real samples. The aim of this diploma thesis was analysis of microflora in control and contaminated brined cheeses. DNA isolated from analyzed samples was used to optimize the PCR course using primers with GC clamp on the distribution of amplicons using DGGE. DGGE products were reamplified after optimization and prepared for DNA sequencing. DNA isolated from analyzed samples was used in real-time PCR with high resolution melt analysis of the amplicons (HRMA). Samples of cheese and bacterial cultures isolated from cheeses were compared by DGGE and HRMA. Comparing the position of the amplicons was found that contaminants may be Bacillus licheniformis, Staphylococcus epidermidis, and Acinetobacter baumanii/ calcoaceticus. Sequence analysis of cheese and pickles amplicons, the presence of Bacillus sp. and other microorganisms spree in five genera were detected. Representatives of the tree genera were cultured. It is considered contamination Bacillus sp., or microorganisms which are not culturable methods used. The method is suitable for the analysis of complex microflora in cheese and pickles after further optimization.
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Identification of probiotic species of genus Lactobacillus
Vystavělová, Růžena ; Trachtová, Štěpánka (referee) ; Rittich, Bohuslav (advisor)
Germs of the Lactobacillus genus form part of the micro flora, the composition of which exercises the influence on the state of health of its host. In view of the fact that at some types of Lactobacillus there were proved clinical effects (e. g. strengthening of the immune system, prevention of diarrheic illnesses and so on), the Lactobacilli have been often used for making fermented dairy products and they form part of food additives because of their probiotic effect. Germs of the Lactobacillus genus and germs of different types of Lactobacillus can be identified by means of PCR based on amplifying specific DNA fragments. The complete bacillary DNA Lactobacillus rhamnosus was separated by the phenolic extraction method. The presence of germs of the Lactobacillus genus was proved by the generic-specific PCR method; the presence of Lactobacillus rhamnosus germs was proved by the species-specific PCR method.
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Identification of probiotic bacteria in complex food matrices and dietary supplements
Cesnak, Filip ; Konečná, Jana (referee) ; Trachtová, Štěpánka (advisor)
Theoretical part of the thesis deals with the general characteristics of probiotic bacteria, their effect on human health and with technological demands imposed on them. Furthermore the thesis deals with actual methods of bacterial identification, especially on the base of polymerase chain reaction. Presence of the declared probiotic bacteria was analysed with the polymerase chain reaction (PCR) and the DNA was isolated from the sample of food additive with the use of magnetic particles.
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Identification of lactic acid bacteria in food products using amplification methods
Jurečková, Nela ; Trachtová, Štěpánka (referee) ; Španová, Alena (advisor)
The aim of the study was isolation of genomic DNA from 7 milk products (yogurts/ yogurt milk) in quality for use it in PCR. Magnetic microparticles (P(HEMA-co¬-GMA)) were used for the DNA isolation. DNA was reversibly adsorbed to the microspheres in the presence of 8% poly(ethylene glycol) PEG 6000 and 5 M sodium chloride. The adsorbed DNA was released from the microspheres in a low ionic strength TE buffer and use as DNA matrix in genus specific PCR Lactobacillus. The presence of DNA of genus Lactobacillus was detected in all analysed products.
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Identification of selected species of lactic acid bacteria in dairy products
Vystavělová, Růžena ; Trachtová, Štěpánka (referee) ; Rittich, Bohuslav (advisor)
Lactic acid bacteria are natural part of the human gastrointestinal tract. They are often used in food supplements and for the production of fermented dairy products. This thesis focuses on the identification of selected species of lactic acid bacteria and bifidobacteria in cheese and dairy products. Bacterial DNA was isolated by magnetic particles P(HEMA-co-GMA) from crude cell lysates from 9 products. Isolated DNA was amplified in genus-specific and species-specific polymerase chain reactions (PCR). The obtained amplicons were detected by agarose gel electrophoresis. The results of PCR were compared with those provided by the manufacturers and there has been declared a match.
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Food products with probiotics
Zemanová, Tereza ; Valicová, Markéta (referee) ; Trachtová, Štěpánka (advisor)
Fermented dairy products containing probiotic microorganisms which are distinguished by favorable effects on the intestinal microflora, are in present time consumed in large quantities. Products range in which microorganisms are contained in recent years expanded greatly. On the market are currently available not only milk, but also meat or vegetable products of this type. The aim of work was to get acquainted with probiotic microorganisms, a description of their use in food industry, and whether they have for us “Homo sapiens sapiens,, favorable or unfavorable effects. In the practical part of work was showed the presence of probiotic bacteria in fermented dairy product using the polymerase chain reaction methods.
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Identification of microorganisms in cosmetic products with probiotics
Langová, Denisa ; Španová, Alena (referee) ; Trachtová, Štěpánka (advisor)
Probiotics products are an integral part of the current market. Products containing probiotics cultures are also cosmetic products. The first part of the study focuses on testing of bacterial survival abilities in the environment of preservatives presented in cosmetic products. Collection strains of genus Lactobacillus were used for these tests. Another part of the study focuses on isolation of bacterial DNA from probiotic cosmetic products Ryor, Yoghurt of Bulgaria, FeminaMed and Lactovit Activit in PCR-ready quality. DNA was isolated by fenol extraction and with magnetic particles. Presence of bacteria was proved by genus and species specific PCRs Lactobacillus. Species specific PCR for identification of Lactobacillus pentosus was optimalized. Species identification was in accord with data declared by producers.
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Biodegradable Nanogels from Biocompatible Polymer Precursors
Oleshchuk, Diana ; Proks, Vladimír (advisor) ; Uchman, Mariusz Marcin (referee) ; Trachtová, Štěpánka (referee)
This doctoral thesis focuses on the development and application of hydrophilic, biocompatible, and biodegradable poly(amino acids)-based nanogels as a new type of delivery system. Within this Ph.D. thesis, nanogelation via horseradish peroxidase (HRP)/H2O2-mediated crosslinking in an inverse miniemulsion was investigated and optimized. The effect of three different surfactants (SPAN 80, TWEEN 85, and AOT) with various concentrations (5 wt% - 25 wt% relative to the dispersed phase with step 5 wt%) on the nanogelation of polyglutamine-based polymer precursor modified with tyramine units (PHEG-Tyr) was investigated. The results indicated that the stabilization of nanogel was most effectively achieved using 20 wt% of the nonionic surfactant SPAN 80. The hydrodynamic diameter (Dh) determined by dynamic light scattering (DLS) was 230 nm, and this size range was further confirmed to be between 200 and 300 nm using (nanoparticle tracking analysis) NTA. Analysis using transmission (TEM) and cryogenic transmission electron microscopy (cryo-TEM) techniques revealed that the nanogel in its dry state exhibited almost spherical shape with a number-average diameter (Dn) of 26 nm and dispersity (Ɖ) of 1.91, and in the frozen hydrate state, the nanogel displayed a larger size with Dn = 182 nm and Ɖ = 1.52,...
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Alternative beverages of probiotic character
Moravec, Štěpán ; Langová, Denisa (referee) ; Trachtová, Štěpánka (advisor)
Bachelor thesis deals with explanation of therm probiotics, properties of each probiotic bacteria genuses. preparation of coffee and tea, and also deals with probiotic coffee and tea and molekular diagostic methods which were used during bachelor thesis. There were used mikrobiological and molecular diagnostic methods for analysis of probiotic coffee and teas. Namely for confirmation of bacterial genus Bacillus and for confirmation of survavibility of Bacillus during high temperatures. Presence of bacterial DNA in samples of coffee and teas was confirmed by conventional PCR method and by real-time PCR method. Survibility of genus Bacillus during high temperaturewas confirmed by PMA-PCR method.
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