National Repository of Grey Literature 470 records found  beginprevious239 - 248nextend  jump to record: Search took 0.03 seconds. 
Refinery and characterization of grape oil
Prchal, Miroslav ; Vítová, Eva (referee) ; Kovalčík, Adriána (advisor)
This bachelor thesis deals with the topic concerning the extraction of wine oil from grape seeds, the refining of the extracted oil and the characterization of grape oil. Grape oil was extracted from the grape seeds obtained from the harvest in September 2019 by the winery Vavricek (Brezi u Mikulova, Czech Republic). The received grape pomace was the mixture of Green Veltliner and Blanc Saugvinon. The oil was extracted from the separated seeds by using liquid extraction in n-Hexane. The extraction yields of grape oil were compared with the literature, involving the different extraction methods as well as different oil plants. For the refining of the grape oil have been applied more steps aiming for the removal of the lipophilic pigments. Different adsorbents of pigments have been applied. The purification efficiency has been proved by the investigation with the thin layer and the high-performance chromatography. Moreover, the gas chromatography was used to characterize the composition of the oil. Finally, the composition profile of the oil obtained by the liquid extraction before and after purification has been compared with the commercial grape oil, which has been received by cold pressing. The results of the work show that the winery waste produced in South Moravia is a valuable raw material, which can be used for the production and different products, e.g., grape oil and pigments (chlorophyll).
Chemical and sensory characterization of cider made from apple cultivars ordinarily grown in Czech republic
Strapcová, Zuzana ; Vítová, Eva (referee) ; Pořízka, Jaromír (advisor)
This master thesis deals with the investigation of selected chemical and sensory characteristics of ciders, which were made from four selected apple varieties. The theoretical part describes the chemical composition of apples, cider, the technology of production and production in the world. The next section describes the analytical methods used to determine chemical characteristics not only in ciders but also in other alcoholic beverages. The experimental part focuses on the determination of chemical characteristics such as the content of organic acids, carbohydrates, total phenolic content, alcohol antioxidant activity and elemental composition. The purpose of the work was to find out how different varieties differ in chemical composition. The produced ciders were subjected to sensory analysis to evaluate the selected cider sensory parameters, which were in the natural state and with the addition of carbon dioxide. The results show that ciders of different varieties differ in chemical composition. Malic acid was the most cider's abundant of the organic acids in the range of 2759 – 4411 mg·l-1. Another acid represented was lactic acid in the range of 166,2 – 288,1 mg·l-1. The glucose content of each cider was determined between 845,3 – 1159,8 mg·l-1and fructose 32,6 – 406,7 mg·l-1. Potassium 944,29 – 1073,98 mg·l-1 was the most represented of all elements. The total phenolic content was determined to be in the range of 164,2 – 214,1 mg of GAE·l-1and the antioxidant activity of 0,192 – 0,318 mg·l-1. These differences in chemical composition were also reflected in sensory evaluation. According to the overall assessment, the best cider was made from the Granny Smith variety, which contained the most organic acids and carbohydrates. It has been found that by adding carbon dioxide, sensory parameters such as colour, taste and smell are altered.
Selected alcohol extracts of Sambucus nigra for use in cosmetology
Balonková, Daniela ; Doležalová Weissmannová, Helena (referee) ; Zemanová, Jana (advisor)
This thesis focuses on the preparation of selected alcohol extracts of elderberry and their use in cosmetology. In the theoretical part are described the botanical properties of the elderberry (Sambucus nigra). There are introduced and characterized bioactive compounds and toxic compounds contained in all vegetative parts of the plant. Attention is mostly focused on compounds with antioxidant properties. The theoretical part also contains a description of basic analytical methods, which are used in the practical part to characterize compounds contained in elder flowers. The practical part focuses on the optimization of the preparation of alcohol extracts with the aim to prepare the extract with the greatest possible content of polyphenols with respect to economy and production costs. Factors such as selection of the appropriate solvent, solvent to plant material ratio, solvent temperature, and extraction time are examined. Based on the total polyphenol concentration measured spectrophotometrically by the Folin-Ciocalteu method, the most suitable solvent is 60% ethanol, the ratio of plant material to solvent is 1:8, the laboratory temperature of solvent and the extraction time of 24 hours.Under these conditions, an ethanol extract is prepared, analyzed and determined selected properties, such as refractive index and density. Rutin, chlorogenic, caffeic and ferulic acids are identified by HPLC with a DAD detector. The pH value of alcohol extract is 5.743 ± 0.006, the refractive index is 1.365 ± 0.02 at 22.7 ° C and the density is 0.9288 gcm-3. By liquid chromatography the concentration of chlorogenic acids is quantified as 0.104 gl-1, caffeic acid as 0.086 gl-1 and ferulic acid as 0.060 gl-1. The extract is incorporated into cosmetic products, that are used in balneology. Prepared products are toilet soap and bath salt.
Study of yogurt composition in process of its preparation
Fajtl, Zbyněk ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
This thesis deals with the study of yogurt preparation and changes during its storage. The theoretical part contains information about parameters affecting both the preparation and properties of the final product. The experimental part describes methods and procedures used for determination of critical parameters such as lactic acid, lactose, glucose and galactose concentrations (HPLC-RI), amounts of streptococci and lactobacilli. The data was graphically evaluated and commented on. The work also included sensory analysis in which the prepared yogurt was compared with commercially available products. The results of this work can serve both consumers and smaller yogurt producers.
Development of method for determination of qualitative parameters of cocoa powder
Vránová, Petra ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
The theoretical part of the master’s thesis is focused on a brief botanical characterization of the cacao tree and its most famous varieties discussed. Furthermore, the chemical composition of cocoa beans is described with an emphasis on theobromine and caffeine. There is also mention of the cocoa beans the cocoa bean processing technology for cocoa liquor and cocoa powder, which are then used in food industry. Additionally there is a shorta short description of the legal requirements relating to cocoa. In this part are also two chapters are devoted to the description of instrumentation of high performance liquid chromatography (HPLC) and inductively coupled plasma optical emission spectrometry (ICP-OES). The experimental part deals with analyzes of cocoa powder, cocoa beans, cocoa liquor and waste cocoa beans sold as a "tea mixture". A total of 10 legislation-recommended parameters have been identified in the listed raw materials, such as caffeine, theobromine and sucrose, heavy metal and potassium, fat content etc. The highest content of theobromine was determined in cocoa powder 178.363 mgl-1, caffeine in cocoa beans 16.096 mgl-1. All samples analyzed contained a little amount of sucrose as expected, the highest concentration was found in the tea mixture samples in both the water: ethanol sample of 84.069 mgl-1, and the sample solution in water of 65.897 mgl-1.
Basic chemical properties of fruits of selected cherry varieties
Chmil, Vojtěch ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
Diploma thesis is focused on chemical characteristics of nine selected sweet cherry varieties in nine parameters. Total and soluble solids were analyzed with these results 13.07–16.58 % for total and 14.67–19.50 °Brix for soluble solids, ash content 0,31–0,39 %, titratable acidity 5.44–9.91 g of malic acid per 1 kg of fresh cherries and formol number 14.45–23.73 ml of 0.1 M NaOH per 100 g of cherries. Then there were analyzed crude proteins content calculated from total nitrogen content determined by Kjeldahl method with results 0.41–0.68 % of crude proteins. Molecular absorption UV/VIS spectrophotometry was used for determination of total phenolic substances 0.30–0.89 g of gallic acid per 1 kg of cherries and total content of anthocyanins 128–848 mg of cyanidine-3-glucoside in 1 kg of cherries. Saccharides were determined by high performance liquid chromatography (HPLC) with ELSD detector. Content of glucose was 45.45–59.49 g/kg and fructose 46.88–60.01 g/kg. All results are compiled using tables and graphs and discussed. Experimental part of the thesis also describes principles and procedures of every analysis, so it can be reproduced. In theoretical part there is described botanical characteristic of cherry tree (Prunus avium L.), active substances contained in its fruits and their use in food industry. At the end of the theoretical part there is described instrumentation of high-performance liquid chromatography.
Adaptogens in the Shizandra chinensis plant
Pospíchalová, Lucie ; Půčková, Helena (referee) ; Kotlík, Josef (advisor)
This diploma thesis deals with plant adaptogens (bioactive substances) in the plant Schisandra chinensis. The theoretical part is focused on characterization of the Schisandra genus, characterization of the Schisandra chinensis as a plant, its properties, occurrence and growing possibilities in the climate zone. Furthermore, The effects of these adaptogens on the organism and the prediction of possible use in food supplements are described. The experimental part deals with the extraction of fruits and leaves from plant Schisandra chinensis. Further, chlorophyll a, chlorophyll b in the leaves extract was determined by UV – VIS spectrophotometry, whereby the optimal amount 3:1 of chlorophyll was confirmed for the plants growing in optimal conditions. Finally, the concentration of the adaptogen schisandrin A in the dried fruits was from different kind of extraction measured by HPLC. In all fruits, schisandrin A was confirmed, but the amount is different in each sample.
Determination of sweeteners and preservatives in energy drinks by HPLC
Zídková, Anežka ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This master´s thesis is focused on simultaneous determination of sweeteners and preservatives in energy drinks by liquid chromatography coupled with DAD and ELSD detection. The method was optimized for determination of aspartame, acesulfame K, saccharin, sucralose, steviol glycosides, benzoic acid and sorbic acid. Analyses were carried out on the Poroshell 120 EC-C18 column (4.6 x 150 mm, 2.7 m, Agilent) using mixture of methanol, acetone and water with formic acid and trimethylamine as a gradient mobile phase at a flow rate 0,5 mL•min-1. Validation parameters were determined (limit of detection, limit of quantification, repeatability and recovery). The validated method was applied on real samples.
Development and validation of the analytical method for the purity assessment of Nalbumin hydrochloride
Děd, Jozef ; Maliarová,, Mária (referee) ; Mrázová,, Viera (advisor)
High Performance Liquid Chromatography is currently used for the purpose of analytical evaluation of drugs. This is mainly because it allows the separation method both, a qualitative and a quantitative, analysis of high selectivity mixture evaluation and sensitivity. The diploma thesis deals with the issue of purity evaluation of pharmaceutical substance Nalbufin hydrochloride. The aim of the experimental part of the diploma thesis deals with the development and validation of the analytical method for assessing the purity of Nalbufin hydrochloride.An HPLC method was developed on a Nova-Pak C18 column. The mobile phase consisted of two components A and B. MF A composition was as follows: 0.97 g of sodium octane sulfonate was dissolved in 900 mL of water to which were added 100 mL of acetonitrile and 2 mL of triethylamine. Created solution was treated with phosphoric acid to pH 2.5. MF B had the following composition: 0.86g of sodium octanesulfonate was dissolved in 800 mL of water to which 200 mL was added acetonitrile of 2 mL of TEA. The resulting pH was adjusted to pH 2.5 with phosphoric acid. gradient MF had the following composition: From zero minutes from 100% A to 30 min. to 0% A. The 30-60min. 0% A, 60-61 min. with a linear change to 100% A, 61-70 min. equilibrium into the original conditions to 100% A at a flow rate of 1 mL/min. In the following section we evaluated the basic validation parameters: linear dynamic range 0.3 - 4.5 g/mL, we calculated the linear regression equation for Nalbuphine in R2 (0.9999), Oxycodone R2 (0.9999) and Noroxycodone R2 (0.9998). The method gave us detection limits for Nalbuphine 0.069 g/mL. Oxycodone had a detection limit of 0.053 g/mL and Noroxycodone 0.048mg / mL. The limist of quantification in these cases were 0.209 g / mL for Nalbuphine, 0.161 g/mL for Oxycodone and 0.147 g/mL for Noroxycodone. Repeatability for the limit of quantification was also set expressed by the relative standard deviation. For Nalbuphine - RSD = 0.40%, Oxycodone - RSD = 2.39% and Noroxycodone - RSD = 1.25% (RSD 7.0%). The following validation parameter was accuracy. The resulting RSD was 0.44% (RSD 5.0%). The last evaluated parameter was robustness. For pH 2.4, the change value was resolution of 1.5% and repeatability of RSD = 0.85%. The change of resolution value for pH 2.6 was 2.8% and repeatability RSD = 1.29% (max. 5% limit). The second factor observed for the robustness was the temperature change of the column. The arithmetic average was calculated from the individual peak areas and relative standard deviation RSD = 3.45% was evaluated with the change of resolution, which had a value of 3.34%. Thus, we can state that the developed chromatographic method has been verified in the givenvalidation parameters and is suitable for determining the purity of Nalbuphine hydrochloride.
Radiolabeling of ramucirumab followed with the study of its internalization in vitro
Gajdoš, Jakub ; Bárta, Pavel (advisor) ; Kuchařová, Monika (referee)
v anglickém jazyce Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Student: Bc. Jakub Gajdoš Supervisor: Mgr. Pavel Bárta, Ph.D. Title of diploma thesis: Radiolabeling of ramucirumab followed with the study of its internalization in vitro. The process of angiogenesis ensures the formation of the bloodstream at the site of its increased need. Therefore, it is not surprising that angiogenesis is often included in the tumor production process, because it provides the tumor cells nutrition supply and metabolite removal. The targeting of angiogenesis has become a key topic of some scientific research. The process of tumor blood supply formation provides a family of vascular endothelial factors (VEGFs) and their respective receptors, which have become the target of the angiogenesis attenuation in a cancer treatment. One of many therapeutics is the monoclonal antibody ramucirumab targeted against VEGF receptor type 2 (VEGFR-2). Radioactive labeling of ramucirumab with a suitable radionuclide could bring benefits in either radiotherapy or radiodiagnostics. The aim of this diploma thesis was the indirect radioactive labeling of monoclonal antibody ramucirumab using 99m Tc as radiodiagnostic nuclide via the chelation agent succinimidyl-6-...

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