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Studying the authenticity of coffee of various geographical origins
Flegr, Šimon ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This diploma thesis researches coffee authenticity problematice, mainly focusing on the authenticity of geographic origin. In the theoretical part of this work, botanical classification is described as well as production technology and processes. The work also includes chemical composition of coffee, describing the major components and changes during production phases. It describes major production areas of the world, in terms of general description and brief history. Problematics with coffee fraud and its identification are also described. Theoretical part also includes general geological description of 17 studied coffee growing regions. Experimental part is devoted to trace amount analysis of selected elements and volatile compounds. The element analysis was conducted using mass spectrometry or optical emission spectrometry, volatile compounds were determined using gas chromatography combined with mass spectrometry detection. Results were statistically described and analyzed, resulting in several discrimination models based on geographic origin.
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Comparison of aroma profile of sweets
Phi, Lan Anh ; Ďubašáková, Mária (referee) ; Vítová, Eva (advisor)
This bachelor thesis is focused on comparing aromatic profile of gummy sweets from three different manufacturers. Sensory quality was monitored at the same time with a focus on flavour. The theoretical part deals with the manufacturing of non-chocolate sweets and aroma active compounds including potential allergens. Furthermore, analytical method for their determination is described. The end is dedicated to sensory methods that were used. In the experimental part, volatile compounds in selected samples of sweets, purchased in the market, were identified and semiquantified by HS-SPME-GC-MS method. For the evaluation of sensory quality, the graphic scales and profile test, were used. In total 134 volatile (aroma) compounds were detected in samples, including seven considered as allergenic (limonene, linalool, citronellol, benzyl alcohol, geraniol, eugenol, hexyl cinnamal). The difference in the number and amount of aroma active compounds as well as sensory properties was dependent on ingredients and manufacturers.
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Chemical composition of wine produced from PIWI cultivars
Michálková, Kateřina ; Vítová, Eva (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis deasl with the chemical charakterization of wine from selected PIWI varieties. The theoretical part describes the general origin and reason for breeding PIWI varieties, a closer characterization of selected three PIWI varieties, Johaniter, Hibernal and Solaris. The next part is devoted to the description of analytical methods that were used to determine the chemical characteristics. The experimental part is developed to the determination of chemical characteristics, namely general characteristics such as alcohol, total phenols, phenolic substances, volatile substances and elemental composition. The results show that are differences between wines from selected PIWI varieties in therms of chemical composition. The most represented organic acid was in the range of 735,1-1286,2mg/l malic acid. This was followed by acetic in the range of 100-400mg/l. The antioxidant activity was determined in the range of 0,2988-0,9683 mmol/l of Trollox and content of total phenols 273,5-390,3mg/l. Of the phenolic substances, gallic acid was the most represented, ranging from 6,9-13,9mg/l. As another, abundant phenolic substances, catechin in the range of 1,6-6,0mg/l was detected. Of the determined elements, phosphorus in the range of 165,4-450,5mg/l was the most represented. Representatives of ethyl ester, ethyl acetate, decanoic acid ethyl acetate and hexanoic acid ethyl ester, were detected as the most abundant volatiles. From the measured data it was evident that wines from PIWI varieties different from standard varieties, especially in the profile of aromatic substances.
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Cyclodextrin derivatives containing covalently bound volatile substances and studies of their release
Palágyi, Attila ; Jindřich, Jindřich (advisor) ; Smrček, Stanislav (referee)
The main aim of the work was to prepare a series of β-cyclodextrin derivatives containing covalently bound volatile compounds via an imine bond. The used volatile compounds were cinnamaldehyde, cyclamen aldehyde, lilal, benzaldehyde, anisaldehyde, vanillin, hexanal, heptanal, citral and 5-methylfurfural. Subsequently, the rate of the release of the active compound, as a function of the environment, was studied by 1 H NMR spectroscopy and static headspace-gas chromatography. Key words: cyclodextrin, aldehyde, imine, kinetics, controlled release
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Issue of substance abuse and school environment
Šmejkalová, Jaroslava ; Pokorný, Ladislav (advisor) ; Přibyl, Ivan (referee)
The thesis investigates the theoretical knowledge about the issue of addictive substances and personal experience with their use for pupils 6. and 8. classes of primary school and for students 2. and 4. year of the grammar school. In the first part of my work, I focused on the definition of basic concepts, the outline of the characters and the possible causes that lead to addiction to drugs, I presented the most commonly used drugs and identified the possibilities of drug prevention. The second part is devoted to a survey in the form of a questionnaire, which directly examines the knowledge and experience with the drug specific age groups of pupils and students. This work could be material for teachers who want to participate in the drug prevention.
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Quantitative composition changes of sex pheromone in Anastrepha fraterculus depending on age
Zyková, Kamila ; Kalinová, Blanka (advisor) ; Rezek, Jan (referee)
Males of South American fruit fly Anastrepha fraterculus form leks and release sex pheromone to attract females during the reproductive behavior. The aim of my diploma thesis was to collect samples of volatiles released by variously old males, subsequently to analyze and to determine the changes in the quantitative composition of the sex pheromone depending on age. The volatiles were trapped on adsorbent, eluted with hexane containing internal standard and analyzed by gas chromatography with mass detection. Males release twenty volatiles, including fourteen terpenes: α-pinene, camphene, -pinene, myrcene, Δ3-carene, limonene, (Z)--ocimene, (E)--ocimene, aromadendrene, trans-α-bergamotene, (Z)-β-farnesene, (Z,E)-α-farnesene, germacrene D, (E,E)-α-farnesene; one aldehyde: nonanal; two alcohols: (3Z)-non-3-en-1-ol, (3Z,6Z)-nona-3,6-dien-1-ol and three lactones: suspensolide, anastrephin a epianastrephin. From the list of named compounds there were proved antenal activity of six compounds in previous work, namely trans-α-bergamotene, (Z,E)-α-farnesene, (E,E)-α-farnesene, (3Z)-non-3-en-1-ol, (3Z,6Z)-nona-3,6-dien-1-ol and epianastrephin.
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Analysis of flower scents Clusia blattophila
Mitrovský, Ondřej ; Kalinová, Blanka (advisor) ; Vaníčková, Lucie (referee)
South American plant Clusia blattophila, growing on Nouraghes of French Guiana, produces relatively large amounts of volatile substances in the fragrance of its flowers. C. blattophila is dioecious plant with different flowering time of monosex flowers Male flowers bloom for one night, while female flowers bloom two nights. The volatiles were adsorbed to the adsorbent and washed out with hexane with internal standard. Analysis was performed by two-dimensional gas chromatography with mass spectrometric detection. The aim of my thesis was to determine the qualitative and quantitative characteristics of flower scents of both sexes. I also studied, whether there are differences in production of the major fragrance component, acetoin, during the first night of blooming. The flower fragrance is complex blend of volatiles. In total, 43 different chemicals were identified. Among them were monoterpenes (α-pinene, camphene, β-pinene, myrcene, limonene, (E)-β-ocimene, camphor) sesquiterpenes (α-copaene, β-caryophyllene, cis-α-bergamotene, trans-α-bergamotene, aromadendrene, (E,E)-α-farnesene, δ-cadinene), aldehydes (1-pentanal, 1-hexanal, 1-octanal, n-decanal), also four ketones (acetoin and its dimer, 2,5-hexanedione, 6-methylhept-5-en-2-one), alcohol butane-2,3-diol, carboxylic acid 2-methylpropanoic,...
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Identification of aroma compounds from Cannabis
Jarošová, Šárka ; Klouček, Pavel (advisor) ; Polesný, Zbyněk (referee)
Hemp is a complex system of chemicals which interacts with one another. The most important chemicals in cannabis are cannabinoids and terpenoids. These compounds evince synergism that makes a number of medicinal effects, e.g. antioxidant, anti-inflammatory, antifungal and analgesic. Volatiles cause aroma of cannabis and have therapeutic effects when it is inhaled.
The main of this study was to identify sensory active compounds in the varieties of cannabis by GC-MS/FID and sensory analysis by GC-MS/O. There were 7 samples of varieties to analysis: Cannatonic (CT) Conspiracy Kush (CK) Jillybean (JB) Jacks Cleaner (JC), Jack Skellington (JS) Nordle (N) and Nurse Jackie (NJ). Selection of these varieties was based on its genetic origin - the ratio of morphological types C. sativa and C. indica. Aromatic compounds were extracted by using SPME fiber. Sensory analysis was performed by one trained sniffer.
The results show that the most represented volatiles in cannabis varieties (both in C. sativa and C. indica) is myrcene. This terpenoid was in the greatest amount in variety of N (33.4%), NJ (29.8%), CT (29.7%) and JB (29.7%). Then beta-caryophyllene had a large number of presence with high ratio in CK variety (21.1%), JC (20%) and NJ (14%). In the varieties with higher level of morphotype C. indica (CK, N), there were limonene and alpha-humulene represented. Results based on the sensory analysis showed, that sensory activity of limonene, linalool and alpha-humulene is higher in varieties with greater ratio of C. indica. The varieties with a higher ratio of morphotype C. sativa were rich in myrcene and terpinolene.
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Monitoring of volatile substances in the fish
Vojáček, Filip ; Urbanová, Klára (advisor)
This Bachelor thesis deals with post-mortem biochemical processes in fish. The theoretical part is focused on describing the ongoing changes in fish and the production of volatile compounds in different species of fish during post mortem changes. Experimental part is focused on monitoring and chemical analysis of volatile compounds from fish under various storage conditions. The analysis is performed on the basis of gas chromatography with mass detector.
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