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Assessment of aroma active compounds in elderberries
Kolibačová, Silvie ; Ürgeová,, Eva (referee) ; Vítová, Eva (advisor)
The aim of this diploma thesis was to determine the aroma active compounds in different varieties of black elderberry (Sambucus nigra L.) and in elder juices that were mixed in different proportions with grape juice. The sensory analysis of these juices was subsequently performed with focusing on their tastiness. The theoretical part deals with the description of the black elderberry, its occurrence, composition and use at home and in industrial processing, as well as a description of aroma active compounds, which have been previously identified in elder by various authors. In the experimental part aroma active substances were identified and quantified in seven selected varieties of elder. Solid Phase Microextraction method was used for their isolation and subsequent analysis was performed by gas chromatography. 39 aroma active compounds were identified totally in fruits of the black elderberry, of which 15 alcohols, 11 aldehydes, 7 ketones, 5 esters and 1 acid. 45 aroma active compounds were identified totally in elderberry juices, of which 19 alcohols, 8 aldehydes, 5 ketones, 7 esters and 6 acids. The sensory analysis of elder juices was performed using ranking test and evaluation using the scales.
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Assessment of aroma active compounds in chosen fruit types
Frechová, Vendula ; Vespalcová, Milena (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with the determination of aroma compounds in selected species of less known fruits (sea buckthorn, cornelian cherry, rowanberry, medlar, japanese quince and chokeberry). The theoretical part is focused on the description of these plants, their chemical composition, possibility of utilization and processing. Aroma compounds were identified and quantified in experimental parts. The aroma compounds were extracted by solid-phase microextraction and analysed by gas chromatography. A total of 45 compounds were identified. This compounds included 17 alcohols, 9 ketons, 8 aldehydes, 6 acids and 5 esters. Concurrently, the sensory evaluation of these fruits was carried out. The profile test and evaluation using graphical scales were used for evaluation of pleasantness and intensity of taste and odour.
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Assessment of aroma active compounds in elderberries
Bazgerová, Petra ; Ürgeová,, Eva (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with the determination of aroma volatile compounds in elderberry. The theoretical part describes the botanical characteristics of elderberry, the incidence and the other known species. Further, this work is focused on the chemical composition of elderberry, there are described in detail the content substances and briefly mentioned are medicinal effects of elderberry. Another theoretical part describes the natural processing of this significant plant and technological production of fruit juices. The second half of the theoretical part deals with the method of determining aroma volatile compounds by gas chromatography in combination with SPME technique, which is suitable for identification of aroma substances. In the experimental part of this diploma thesis SPME-GC method was applied to some samples of elderberry and aroma volatile compounds of individual samples of elderberry were determined.
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Aromatic substances of wine
Stávková, Markéta ; Vespalcová, Milena (referee) ; Ruibar, Jiří (advisor)
This bacherols thesis consists of two parts, of theoretical part and practical part. The theoretical part delimits wine-producing regions in Czech republic, explains growing of grapevine. The thesis is concerned with the soil classification, amount of mineral element and decribes the quality and aroma of a wine. It´s briefly concerned with bouquet of wine during wine production. Deals with chemical changes in must during fermentation using yeast. The practical part is concerned with soil analysis of vineyard Rajhradské Klášterní. The goal of this experimental part was to finding out amout of mineral elements in samples and their comparison between the four vineyard. Aromatics are analyzed by gas chromatography and sensory analysis.
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The influence of microflora on the sensoric characteristic of the wine
Petrášová, Ludmila ; Vítová, Eva (referee) ; Vránová, Dana (advisor)
The bachelor thesis is focused on the influence of the microflora on the sensory characteristics of the wine. The theoretical part provides information of the botanical description of Grüner Veltliner grape wine varietal, as well as its chemical composition, the white wine processing technology, and the influence of yeast on the aroma profile of this varietal. The experimental part describes the method of determining the aroma-active compounds by gas chromatography in combination with solid phase micro-extraction (SPME-GC). The object of the study was to measure samples of four different cider varieties of Grüner Veltliner during the fermentation process, and to compare the aromatic compounds in the cider with the indigenous yeast and in the cider where spontaneous fermentation was used.
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Assessment of aroma active compounds in unconventional fruit types
Krchňavá, Petra ; Divišová, Radka (referee) ; Vítová, Eva (advisor)
This bachelor’s thesis deals with the determination of aroma compounds in selected drinks produced from chokeberry (Aronia melanocarpa). The theoretical part is focused on the description of this plant, its chemical composition, properties, influence on the human body and possibility of utilization and processing. In the experimental part the aroma compounds in samples of sirup and liqueur from chokeberry were identified and quantified. . The aroma compounds were extracted by solid-phase microextraction and analysed by gas chromatography. A total of 43 compounds were identified. Concurrently, the sensory evaluation of samples was carried out. The profile test and evaluation using scales were used for evaluation of overall pleasantness and intensity of taste and odour. The contribution of selected descriptors (fruit, sweet, acid and other taste and odour) to overall sensory quality of samples was also judged.
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Assessment of aroma active compounds in chosen fruit types
Rodzíková, Martina ; Vespalcová, Milena (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the assessment of aroma active compounds in less known berries, gooseberries. In the theoretical part the general characteristics, biological signs and properties of selected varieties, chemical composition and structure of the components, drug effects, the possibility of processing and use of gooseberries are mainly described. The main aim of this thesis was to determine aroma active substances in selected varieties of gooseberry fruits using SPME-GC method. Aroma active compounds were first extracted by solid-phase microextraction and then assessed by gas chromatography.
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The chosen validation parameters of method for assessment of aroma compounds in elderberries
Christovová, Silvia ; Ürgeová, Eva (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the assessment of aroma active compounds in elderberries (Sambucus nigra L.). In the theoretical part the chemical composition and attributes of elderberries are described. Brief information on their healing properties is also given. The possible processing methods in food industry, as well as the traditional means of use at home, are discussed furthermore. Following chapters describe the gas chromatography method combined with the technique of solid-phase microextraction, utilized for the specification of aroma active compounds. The validation of this method is also included. The aim of the experimental part of the work was to verify a set of the selected validation parameters of the SPME-GC method, specifically linearity, the limits of detection (LOD), the limits of quantification (LOQ) and repeatability. Subsequently, the SPME-GC method was applied on the chosen elderberry juice samples. In total, 37 different volatile aroma active compounds were identified and quantified, 15 of which belonged to alcohols, 9 to aldehydes, 5 to ketones, 5 to esters and 2 other compounds. The chemical composition of individual samples was not uniform; no single sample contained all of the identified compounds.
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Assessment of aroma active compounds in unconventional fruit types
Melikantová, Marcela ; Pšenáková, Ivana (referee) ; Vítová, Eva (advisor)
The aim of this bachelor thesis is the assessment of aroma active compounds in unconventional fruit types, sea buckthorn (Hippopha rhamnoides L.) was chosen as a model sample. The first part is focused on the description of these plants, their chemical composition and use. The experimental part is focused on identification and quantification of aroma compounds in chosen cultivars of sea buckthorn using SPME-GC-FID method. In total, eleven cultivars were analysed. The cultivar Krasna was found as having the most aromatical profile (the highest content of aroma compounds identified). Ethanol, 3-hydroxy-2-butanone, ethanal, butyl acetate and acetic acid were the most often occuring compounds.
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The possibilities of the assessment of aroma active compounds in elderberry juice
Kolibačová, Silvie ; Vránová, Dana (referee) ; Vítová, Eva (advisor)
This bachelor thesis is a literature research, which deals with the characteristics of black elderberry, its occurrence, types and how to use it particularly in medicine and food industry. The next section describes the production of fruit juices and methodologies for the determination of aromatic compounds in elderflower juice, which were selected for future measurements. This is the method solid phase microextraction (SPME) and gas chromatography (GC). Almost a hundred different volatile compounds are given in the literature, which are located in different cultures of elderberry and their presence and quantity are dependent not only on the culture, but also on the season, the environment and the method that was used for extraction and determination of aromatic compounds.
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