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The content of aroma active compounds in sweets
Paulišová, Sabina ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
This bachelor thesis focuses on identification of aroma active compounds in selected samples of non-chocolate sweets. Based on the results obtained, the aromatic profile of the individual samples is compared. The theoretical part deals with aroma active compounds, legislation and technology of manufacturing non-chocolate sweets. Further experimental technique and the methods used in practical part, namely solid phase microextraction and gas chromatography with mass spectrometry detection are presented. In the experimental part volatile aroma active substances were identified in green colored jelly candy samples available in the common market. For this purpose, the HS-SPME-GC-MS method was used. The individual samples differed in type and number of volatile compounds, depending on the manufacturer. In total 72 different compounds, including 11 aldehydes, 14 alcohols, 27 esters, 1 heterocycle, 8 carboxylic acids, 6 ketones, 4 hydrocarbons and 1 sulfur compound were found.
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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 chemical reactions products in the prebiotic atmospheres
Manduchová, Ivana ; Slavíček,, Pavel (referee) ; Mazánková, Věra (advisor)
The diploma thesis is focused on the study of chemical reaction products in prebiotic atmospheres. The theoretical part deals with the main theories of composing the atmosphere of the early Earth, hypotheses of the origin of life and genetic code in the form of RNA, the atmosphere of the moon Titan and the basic characteristics of the gliding arc discharge, and the analytical techniques used in the diploma thesis. In the experimental part, study of products was carried out by experimental atmospheric simulations in a special stainless steel reactor in various mixtures of gases N2, CH4, CO2 and O2. The electrical discharge for atmospheric simulation was generated by an electrode configuration for the gliding arc discharge and glow discharge. Detection and identification of chemical reaction products was performed by Gas Chromatography with Mass Spectrometry (GC-MS) and Flame Ionization Detector (GC-FID), Testo 350 M/XL and Proton Transfer Reaction Mass Spectrometry (PTR-MS). A theoretical kinetic model was created to predict and confirm the detected products. During the experiments, the dependence of the product intensity on changes in the composition of the gaseous mixture and the applied value of the electric current was also observed.
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Influence of aroma compounds on sensory quality of sweets
Motúzová, Eliška ; Zemanová, Jana (referee) ; Vítová, Eva (advisor)
This master´s thesis is focused on determination of aroma active compounds in non-chocolate sweets and their influence on sensory quality/flavour. The theoretical part describes production of non-chocolate sweets, characterizes aroma active compounds including allergenic ones, method for their determination by solid-phase microextraction and gas chromatography with mass detection. For experimental part were used as model samples gummy candies purchrased in regular market. Four flavors were used, specifically yellow (lemon), green (apple), red (strawberry) and orange (orange). The HS-SPME-GC-MS method was used to identify volatile aroma active compounds. To evalutate the sensory quality were used scales, a profile test, and a time course evaluation. Owerall 120 volatille compounds were identified including 8 allergens.
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Aroma active compounds of selected types of herbs
Škutová, Pavla ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with the identification of aroma active compounds in medicinal herbs. The group consists of 5 types of herbs: lemon balm (Melissa officinalis), pot marigold (Calendula officinalis), clary sage (Salvia sclarea), milk thistle (Silybum marianum), goat’s rue (Galega officinalis). These plants are known for their positive effects in folk medicine. The SPME-GC-MS method was chosen to characterize the fragrances. During the identification of volatile compounds, emphasis was put on suspected fragrance allergens listed in EC Regulation 1223/2009 in Annex III. Overall 106 compounds were identified together with 8 allergens in lemon balm, pot marigold contained 104 compounds with 7 allergens included, 82 compounds including 5 allergens in clary sage, 73 compounds were identified in milk thistle including 6 allergens and 110 compounds with 9 allergens included in goat’s rue.
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Mitochondria as a target of anticancer therapy.
Dvořák, Aleš ; Ježek, Petr (advisor) ; Poučková, Pavla (referee) ; Vecka, Marek (referee)
Mitochondrial isocitrate dehydrogenase 2 (IDH2) catalyzes reductive carboxylation (RC, reverse Krebs cycle pathway) and 2HG synthesis (2HG) - metabolite of which many scientists are interested. 2HG may be concurrently synthetized in cytosol by IDH1. RC is involved in anabolic reactions necessary for cell proliferation - produces citrate, fatty acid precursor - especially in hypoxia. IDH2 and IDH1 are not the only enzymes that are involved in 2HG synthesis. Recently, several enzymes, which participate in 2HG production, have been discovered. 2HG is useful in cancer diagnostics due to its overproduction by transformed cells. Moreover, 2HG may cause epigenetic changes via inhibition of 2-oxoglutarate dependent dioxygenase. In this work, the importance of RC and 2HG synthesis in cancer and healthy cells was investigated by gas chromatography with mass spectrometry detection as well as IDH2 influence. We found that IDH2 significantly participates in reverse RC and 2HG synthesis in breast cancer cell lines and uses glutaminolysis as a supplementary anaplerotic pathway. RC is increased by hypoxia, inhibition of respiration, and decreased by activation of respiration or hypocapnia. We confirmed 2HG synthesis and RC in healthy cells (fibroblasts, breast epithelial cells etc.) as well as in cancer cells....
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Natural sources and sinks of volatile chlorinated hydrocarbons in the spruce forest ecosystem
Štangelová, Pavla ; Tesařová, Eva (advisor) ; Pavlík, Milan (referee)
Biogeochemical cycle of chlorine, particularly the formation of organically bound chlorine is still not well understood. In continental ecosystems chlorides act as source of chlorine, and also as a stress factor. Chlorides originate from precipitation of marine cloud masses. Organically bound chlorine in the environment is formed naturally by biotical and abiotical way. The biotical factors are microorganisms, plants, soil enzymes and animals. Volatile chlorinated hydrocarbons (VOCl) represent one group of organically bound chlorines. Several volatile chlorinated hydrocarbons reacts with atmospheric ozone, consequently causing depletion of the ozone layer. The most important known terrestrial source of volatile chlorinated hydrocarbons is the spruce forest ecosystem. Chlorine in the soil can be transformed by microorganisms into organically bound chlorine or translocated by transpiration stream in plants, where they are also transformed enzymatically into organically bound chlorine, and both of them can be emitted into the atmosphere. Too large amounts of chloride can affect the physiological functions of plants. In this thesis experiments were designed for measuring the natural emissions of volatile halogenated hydrocarbons from plants and fungi, with various periods of incubation, and also to...
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Identification and quantification of biomarkers of gastrointestinal diseases using mass spectrometry
Pospíšilová, Veronika ; Španěl, Patrik (advisor) ; Jelínek, Ivan (referee)
6 Abstract This thesis focuses on the identification and quantification of volatile metabolites in the exhaled breath that might be used as possible biomarkers of Gastroesophageal Reflux Disease. Animal tissue samples were exposed to conditions simulating the gastric environment to identify specific volatile compounds that would be chosen for real-time quantification in exhaled breath of GERD patients and healthy controls using selected ion flow tube mass spectrometry. Solid phase microextraction, was used in combination with gas chromatography mass spectrometry, for qualitative analyses of the headspace of these samples. Only acetic acid was significantly elevated and so it has been elected for the quantitative analysis in the breath of the patients. The median concentration of acetic acid measured by SIFT-MS in the exhaled breath of twenty-two GERD patients was found to be higher (85 ppbv) in comparison to the control group (31 ppbv). The results show that breath acetic acid could be valuable marker for GERD diagnosis and monitoring.
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The role of neuroactive steroids in pregnancy and their importance in prenatal diagnosticsSteroidogenesis in the third trimester of pregnancy and mechanisms leading to the start of labor
Pašková, Andrea ; Pařízek, Antonín (advisor) ; Procházka, Martin (referee) ; Tošner, Jindřich (referee)
Steroid hormones act through two mechanisms. The first is the classical genomic level, which acts at a relatively slow pace from hours to days. The second non-genomic mechanism of steroid activity can influence cellular function during seconds or even milliseconds. During pregnancy both mechanisms take place. Steroid hormones that act non-genomically and influence neuronal excitability are called neuroactive steroids. The aim of this study was to measure the levels of steroid hormones and examine their relationship to the physiology and pathophysiology of pregnancy. The physiological importance of increased placental progesterone production, lowered production of 5B-pregnanone steroids and increased activity of steroid sulfotransferase with gestational age have been intensely discussed. On the basis of our results, we have proposed an alternative mechanism of maternal progesterone synthesis during pregnancy (progesterone, or the gestagen stabilizing activity of the myometrium = continuation of pregnancy). In contrast to previous results our observations indicate that gestagens arise from precursors in the fetus (from pregnenolone sulfate). This mechanism is closely connected with the distribution of placental oxido-reductase. Data from this study show an increasing trend in the conversion of...
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Aroma active compounds in fruit distillates
Kocinger, Oskar ; Veselá, Mária (referee) ; Vítová, Eva (advisor)
This work deals with the identification of substances responsible for the taste and aroma of fruit spirits. Solid phase microextraction method coupled with gas chromatography and mass spectrometry (SPME-GC-MS) was used for extracting and identifying volatile substances present in a total of six samples of fruit spirits, namely 3 samples for plum distillate and 3 samples for apricot distillate. The results of the individual analyzes were compared and the most frequently occurring substances were identified. These compounds are most likely responsible for the typical aroma of fruit spirits of this kind.
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