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Modern herbs in the food industry
Adamczyková, Michaela ; Řezáčová, Veronika (referee) ; Vítová, Eva (advisor)
The bachelor thesis deals with the issue of volatile (aromatic) compounds of Plectranthus spp. and Echinacea purpurea. The theoretical part focuses on the general characteristics of the above mentioned herbs, the content of their bioactive and volatile compounds, and on their importance as well as on their potential use in the food industry. Using the HS-SPME-GC-MS method, the volatile compounds of the herbs and extracts prepared from them were identified and quantified in the experimental part. A total of 11 volatile compounds were found in all the samples. The most frequent one in the sample of a fresh Plectranthus was 3-carene (13,78%) as well as in the sample of dried Plectranthus (14,85%). However, in the Plectranthus extract it was -selinene (17,84%). As for Echinacea, it is germacrene D (18,64%) in the sample of a fresh one, camphor (58,46%) in the one of dried Echinacea and -copaene (20,42%) in its extract.
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Effect of roasting on the sensory profile of coffee
Šajdlerová, Kristýna ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with the effect of roasting on the content of carbohydrates and aromatic compounds in coffee. It also studies changes in coffee acidity based on different level of roasting. In the practical part there was measured pH, it was conducted setting of glucose, fructose and sucrose content by liquid chromatography, analysis of aromatic compounds using gas chromatography and also sensoric analysis of 17 types of coffee. Each one was roasted using two different temperatures (210 °C and 240 °C). Based on the statistical processing of basic chemical analysis and sensory analysis, significant differences were found between determined parametres of coffee samples roasted at 210 ° C and 240 ° C. Processing of results of sensory and chemical analysis of coffee samples did not manage to differentiate coffee samples from each other based on their geographic origin. At a lower level of coffee roasting there was found weak, but statistically significant correlation between the results of the sensory analysis and the content of aromatic compounds, while for the higher degree of coffee roasting no correlation was found.
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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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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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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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Synthetic aromatic substances in wastewaters
Tylichová, Petra ; Čáslavský, Josef (referee) ; Vávrová, Milada (advisor)
Synthetic fragrances are artificially synthetised organic compounds which are used as fragrant substances in assorted personal care products, perfumes, cosmetics, soaps, detergents, cleansing articles, etc. So-called musk compounds creates significant group of synthetic fragrances which are distinguished by specific fragrance reminiscent of musk. Recently great attention is devoted to musk compounds because they were proved in different units of environment. The aim of diploma thesis was determination of selected linear musk compounds (arocet, aroflorone, linalool 925, lilial, isoamyl salicylate) in real samples of waste water in the influent and effluent from the sewage treatment plant Brno-Modřice. At first optimization of selected method was performed and then this method was used for own determination. Analytes were extracted by solid phase microextraction (SPME) from sample. Method of gas chromatography with mass spectrometry was used for own analysis. The results were used for evaluation of efficiency of removing linear musk compounds from waste water.
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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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Verifying of the method for assessment of allergenic aroma compounds in sweets
Maňáková, Adriena ; Diviš, Pavel (referee) ; Vítová, Eva (advisor)
This thesis deals with the assessment of aroma active compounds in non-chocolate confectionery and their influence on sensory quality. In the theoretical part the production technology of non-chocolate confectionery from raw materials to final product is described. Furthermore, aroma active substances, including those potentially allergenic, are characterized, and the method for their determination by solid phase microextraction and gas chromatography with mass spectrometry is briefly described. Sensory analysis and sensory evalutation methods are briefly desribed. Within expermental part of the work selected parametres of the HS-SPME-GC-MS method were optimized, aroma compounds in samples of hard candies were identified, and 24 potentially allergenic aroma substances were identified and quantified. Finally, a sensory analysis of these samples was performed. Differences in the number and type of volatile compounds were found between the samples. Overall 393 compounds were indetified including 19 allergens.
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Aroma active compounds of selected types of medical herbs
Pecinová, Ester ; Diviš, Pavel (referee) ; Vítová, Eva (advisor)
This thesis deals with aroma active compounds of selected types of medicinal herbs, specifically lavender (Lavandula officinalis), peppermint (Mentha piperita), sage (Salvia officinalis), St. John’s wort (Hypericum perforatum) and hyssop (Hyssopus officinalis). In the theoretical part the single herbs were characterized including botanical description, chemical composition, medicinal properties, adverse effects and the practical use; aroma active compounds present in herbs are also emphasized. Based on the literature search, gas chromatography coupled with mass spectrometry as currently the most frequently used method, was chosen for the assessment of aroma compounds. Solid Phase Microextraction was used for isolation of volatile compounds from dried herbs. Within experimental part of the work selected parameters of the SPME-GC-MS method were optimized, aroma compounds in samples of herbs were identified, and twenty four suspected fragrance allergens due to the Regulation (EC) N° 1223/2009 were also identified and quantified. Overall 69 compounds were indetified together with 2 allergens in lavender, 59 compounds including 5 allergens in peppermint, sage contained 49 compounds with 4 allergens included, 41 compounds were identified in St. John’s wort including 4 allergens and finally 64 compounds with 4 allergens included in hyssop.
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Confirmation of identification of volatile substances by calculation of retention indexes
Cviková, Sára ; Šimíčková, Adéla (referee) ; Vítová, Eva (advisor)
This bachelor thesis is focused on verifying the identification of volatile compounds using retention indices. The HS-SPME-GC-MS was used for determination. First part is theoretical and is focused especially on the brief definition of terms such as gas chromatography, retention time, retention index, mass spectrometry, however, the chemical and physical description of the CBD oil sample, which was used to prove the function of retention indices, is also mentioned. The standard homologous set of n-alkanes (C8 - C20) was used to determinate the retention indices, which was analyzed under the same conditions as the sample of CBD oil. In the CBD oil 38 volatile compounds were successfully identified. Their identification was confirmed by calculating their retention indices using the equation by H. van der Dool and D.J. Kratz, and comparing with tabulated values for the same type of chromatographic column.
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