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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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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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Assessment of aroma active compounds in selected type of cheese
Páral, Marek ; Mahdalová, Martina (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the determination of aroma active compounds in white mold cheeses, i.e. soft, mold cheeses maturing from the surface. In the theoretical part, cheeses are generally characterized, their chemical composition, properties and process of production are described. After that It´s focused on aroma active compounds. The metabolism of their formation in cheese and their determination by means of solid phase microextraction and gas chromatography with mass detection are described. In the experimental part of the bachelor thesis, the SPME-GC-MS method was used for identification and semiquantitative determination of aroma active compounds in three samples of white mold cheeses made in the Czech Republic purchased in a market. Comparison of cheeses showed differences in the number and types of determined compounds as well as in total contents. A total of 66 volatile compounds were identified in samples; of those 1 aldehyde, 17 alcohols, 19 esters, 9 carboxylic acids, 15 ketones, 1 sulphur compound ¨ and 3 hydrocarbons.
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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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Extraction of anthocyanin pigments from elderberries pomace
Lošková, Tereza ; Pořízka, Jaromír (referee) ; Vespalcová, Milena (advisor)
This Diploma thesis deals with the production of the concentrate from the Elderberry marc extract (Sambucus nigra L.). The basic chemical characteristics in this concentrate were determined. The theoretical part of the thesis deal with the botanic characteristic of the Elderberry and its berries. The characteristic of the phenolic compounds, mainly anhocyanins was summarized. The use of the anthocyanin pigments in the food industry, the possibilities of their extraction and the concentrate production was discussed. Thereafter the methods of the anthocyanin content and the phenolic content determination were described. In the experimental part of study, the production of the anthocyanin rich extract from Elderberry marc was optimized. The extraction of the marc by the 1:1 ethanol/water (V/V) solvent with the ratio marc/solvent 1:2 (w/V) showed the most convenient. The production of the concentrate followed. During the concentration on the rotary evaporator the pigment degradation was investigated. The degradation decreased with the decrease of the temperature. The final concentrate was prepared from the extract on the rotary evaporator by 45 °C for 15 minutes. This product had the 7times lower volume compared to the initial extract. In the final concentrate come of the chemical characteristic were determined. By liquid chromatography (HPLC) the major pigments cyanidin-3-sambubiosid and cyanidin-3-glucosid were determined. Their total content was determined to 34,9 gl-1. The total anthocyanin content was determined by pH differential method to 7,1 gl-1 (expressed as cyanidin-3-glucoside equivalent). The total phenolic content was determined to 27,1 gl-1 (expressed as gallic acid equivalent) by Folin-Ciocalteu method. By electron paramagnetic resonance the increase in antioxidant activity with the increase in concentration was found. Up to 42 aromatic compounds was determined in Elderberry marc, its extract and the final concentrate.
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Comparison of aroma active compounds of selected types of cheese
Brožová, Michaela ; Zemanová, Jana (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with the determination of aroma active substances in selected white mold cheeses, which are/are not awarded with the „Protected Designation of the European Union“ and their mutual comparison. In the theoretical part cheeses are characterised , including general production technology. The white mold cheeses are then described in detail. This is followed by the literary search dealing with the problematic of aroma active substances in cheeses. In conclusion of the theoretical part the method of their determination using solid phase microextraction and gas chromatography with mass detection is described. The SPME-GC- MS method was chosen for the experimental part of the determination of aroma active substances in selected white mold cheeses. A total of 12 cheeses were analyzed, of which 6 were Czech and Slovak and 6 were French with a protected designation of origin. The differences between individual samples were found in the number and type of the identified volatile compounds. A total of 78 volatiles were identified in selected cheeses, of which 20 were alcohols, 19 esters, 12 ketones, 11 acids, 4 sulfur compounds, 3 hydrocarbons, 3 lactones, 2 aldehydes, 2 phenols, 1 nitrogen compound. The cheeses were compared in terms of the identified compounds, and finally the results were statistically evaluated by the PCA method.
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The content of aroma compounds in sweets
Polochová, Petra ; Vespalcová, Milena (referee) ; Vítová, Eva (advisor)
This bachelor thesis focuses on identification of aroma active substances in samples of non-chocolate sweets. The theoretical part deals with the legislation and technology of manufacturing non-chocolate sweets, characterization of aroma compounds including those which could be allergenic. Furthermore this thesis describes a method of their determination using solid phase microextraction and gas chromatography with mass spectrometry (SPME-GC-MS) is described. In the experimental part, the chosen method SPME-GC-MS method was used to identify volatile aroma active substances in selected samples of jelly sweets purchased in a conventional market. The substances that are potentially allergenic were also quantified. The single samples differ in number and type of volatile compounds depending on producer and flavour. Altogether 246 compounds were identified, of which 30 hydrocarbons, 66 alcohols, 7 ethers, 20 aldehydes, 24 ketones, 56 esters, 13 carboxylic acids, 3 phenols, 16 heterocyclic compounds, 6 lactones and 5 others (linalooloxide; methylsulphonylmethan; dimethylsulphoxide; 1,1-diisobuthoxy-isobutane and propanamide).
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Preparation and characterization of plant extracts for application to syrups
Šandová, Lucie ; Zemanová, Jana (referee) ; Vítová, Eva (advisor)
The aim of the diploma thesis was to produce herbal syrups from three selected herbs of the Lamiaceae family - Salvia officinalis, Melissa officinalis and Mentha piperita. First, extracts were prepared from these herbs by maceration in 25% of ethanol (60°C, 90 min). From the prepared herbal extracts, herbal syrups were made by mixing with syrup base (65% sucrose solution + lactic acid 2 g.l-1) in different ratios (2:1, 1:1, 1:2 - extract: base of the syrup). On the basis of sensory evaluation, a ratio of 1:1 was selected as optimal. The extracts and syrups produced were characterized in terms of volatile profile, phenolic content, antioxidant activity and antimicrobial activity. The produced syrups were also evaluated sensorially using scales, profile, and order test, and compared with similar commercial samples (Baťkovy sirupy s.r.o.). The HS-SPME-GC-MS method was used for the determination of volatile substances, the Folin-Cicalteu method for total phenolics, the TEAC method for antioxidant activity and the well and disc diffusion method for antimicrobial activity. 36 volatiles were found in model sage syrup, 29 in commercial syrup; 20 volatiles were found in model lemon balm syrup, 32 in commercial syrup; 25 volatiles were found in model mint syrup, 41 in commercial syrup. The quantitative distribution of the most important compounds in the commercial and manufactured syrups differed, with terpenes predominating in all samples. The content of phenolic compounds in syrups decreased in the order sage (570.1 mg.l-1) > lemon balm (378.9 mg.l-1) > mint (96.5 mg.l-1), antioxidant activity in the order lemon balm (332.0 µg.ml-1) > sage (185.6 µg.ml-1) > mint (115.8 µg.ml-1). Commercial syrups showed significantly higher phenolic compound content and antioxidant activity than manufactured syrups for all three herbs. In terms of sensory quality, mint syrup was considered the most palatable and sage syrup the least palatable (mint > lemon balm > sage); only in the case of lemon balm was the manufactured syrup considered better, more palatable than the commercial sample. It was reasonably liquid, clear of a pleasant colour, with a distinctly sweet, slightly herbaceous taste and a pleasant aroma.
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Accuracy of the method for assessment of allergenic aroma compounds
Rychetský, Matěj ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the verification of the accurancy of the method for determination of potentially allergenic substances in confectionery. In the theoretical part the synthetic and natural fragrances, which are present in foodstuffs are described. Furthermore, the method of solid phase microextraction in connection with gas chromatography with mass spectrometry, which was used in the measurement, is briefly characterized. Finally, the basic criteria measured in the validation of the analytical method are described. In the experimental part, the repeatability and reproducibility of the HS-SPME-GC-MS method for the determination of potentially allergenic substances in candy samples was verified. It was found by the measurement that the used method is suitable for qualitative determination (based on retention times), but the method shows minor inaccurancies in quantitative determination (determination based on peaks area) and it will be improved in following experiments.
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Comparison of aroma profile of goat vs. cow milk
Pospíchalová, Alžběta ; Saláková,, Alena (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with the comparison of aroma compounds in goat and cow milk. The content of aroma active substances in samples of goat and cow milk, which were analyzed by HS-SPME-GC-MS method, is monitored. In the theoretical part, milk is characterized, its formation in the dairy mammary gland is described, its composition including an overview of aromatic active substances, physical and chemical as well as its sensory properties, milk defects and differences between cow's and goat's milk are described. Further, gas chromatography in combination with solid phase microextraction technique in tandem with mass spectrometry is described. In the experimental part, 13 samples of goat and 8 samples of cow milk were subjected to HS-SPME-GC-MS analysis. Samples were analyzed fresh and after heat treatment. Altogether, 78 volatile substances were identified in the samples. Ketones were the most numerous, aldehydes, alcohols and carboxylic acids were the most abundant chemical groups. There were differences between samples in number as well as in content of the identified compounds, 64 in goat milk and 48 in the cow milk.
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