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Possibilities of using spices in the production of ham salami
Vershinina, Alina ; Szotkowski, Martin (referee) ; Mikulíková, Renata (advisor)
This bachelor's thesis focuses on the possibilities of using different spices, specifically cumin, nutmeg, allspice and marjoram, in the production of ham cuts. The aim of the work is to investigate the effect of these spices on the taste, aroma and other sensory properties of the ham cut and to assess their contribution to improving the overall quality of the product. The methodology includes the collection of samples of ham cut with various additions of spices, the performance of sensory analysis and chemical analysis for the identification and quantification of phenolic substances present in individual spices. Subsequently, the results will be evaluated and their significance for the production of ham cuts will be discussed. The results of this work could contribute to a better understanding of the use of spices in the production of meat products and provide data for the optimization of recipes and processes in the food industry.
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Determination of selected bioactive substances in grapes
Havlíková, Markéta ; Trachtová, Štěpánka (referee) ; Vítová, Eva (advisor)
The subject of this thesis was the determination of selected bioactive substances in grapes and the subsequent comparison of differences between the samples. Two fractions of grapes (skins and pulp with seeds) of 4 grape varieties - Hibernal, Johanniter, Riesling and Aurelius - were analysed. Two methods were used for the determination: for phenolic substances, high-performance liquid chromatography with mass spectrometry and for volatile substances, headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry. For each of these methods, the optimal extraction technique was first selected and then used for the analysis of all samples. The linearity of the external standard method was also verified with a reliability coefficient R2 in the range of 0.9650-0.9989 for high-performance liquid chromatography with mass spectrometry and 0.8571-0.9999 for headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry. 63 volatile and 9 phenolic compounds were identified in the samples. From these, specific compounds of grapes (20 volatile compounds and 5 phenolic compounds) were selected. On the basis of the amount of observed compounds, the two grape fractions and subsequently the grape varieties were compared with each other. There were differences in the content of selected compounds between grape fractions and across varieties, which could probably be due to the geographical origin of the samples.
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Bioactive compounds in cruciferous vegetables
KOVAČIKOVÁ, Karolína
This diploma thesis deals with bioactive compounds in cruciferous vegetables (Brassicaceae). The thesis aimed to determine the content of phenolic compounds, chlorophyll A, chlorophyll A+B, carotenoids and also vitamin C, in selected species of cruciferous vegetables: Brussel sprouts (Brassica oleracea var. gemmifera), Fodder Kale (Brassica oleracea var. acephala), Curly Kale (Brassica oleracea var. sabellica) and Ornamental Cabbage (Brassica oleracea var. capitata). The highest amount of chlorophyll A was represented in the sample of ornamental red cabbage, variety Pigeon Victoria F1. The highest content of chlorophyll B, chlorophyll A+B, carotenoids and also vitamin C was determined in curly green kale, a variety Tuscan. The highest amount of phenolic compounds was measured in curly red kale, variety Scarlet.
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Influence of beer protein on foam stability
Benda, David ; Štursa, Václav (referee) ; Pořízka, Jaromír (advisor)
This bachelor thesis deals with the influence of beer proteins, phenolic compounds, bitterness and selected metal ions on beer foam stability. The theoretical part describes beer foam from the physical aspect, beer foam stability and its measurement and the factors that positively or negatively influences the stability and quality of the beer foam. In the theoretical part are described selected proteins that influence beer foam. In theoretical part is described the origin and technological significance of proteins. The experimental part is dedicated to the measurement of beer foam stability with the NIBEM method, the analysis of total protein content, the analysis of total phenolic content, bitternes and element analysis of beer samples. Measured data indicated correlations between protein content, phenolic compounds content, bitterness and metal ions with the beer foam stability. The results show that proteins and phenolic compounds as isolated parameters don’t essentialy affect the beer foam stability. It was found out, that bitterness as isolated parameter influences the beer foam stability the most.
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Isolation and characterization of beta-glucans of natural origin
Ratsilouskaya, Lizaveta ; Hoová, Julie (referee) ; Márová, Ivana (advisor)
The bachelor thesis deals with the characterization of natural beta-glucans and other active substances isolated from macroalgae and yeasts. The used macroalgae samples differ in the pigment, origin and method of algae processing. The theoretical part focuses on seaweed and yeast species, beta-glucans, their sources and biological effects, other biologically active substances (such as polyphenols and antioxidants) and finally on methods for determining these biologically active substances. In the practical part, samples of selected macroalgae were analyzed, namely samples of Arame, Nori, Kombu, Wakame, Hijiki and Spaghetti. Aqueous, ethanol and acetone extracts of these algae were prepared in this work. The aqueous extracts were used for spectrophotometric determination of phenolic substances, flavonoids and antioxidant activity by the ABTS method. Furthermore, ethanol and acetone extracts of said macroalgae were used to determine total chlorophyll and carotenoid content spectrophotometric. The work also focused on beta-glucan content, analyzing macroalgae and yeast R. toruloides. Arame and Nori algae and R. toruloides were high in beta-glucans. However, beta-glucans were very low in other macroalgae.
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Biologically active substances of the Gotu kola plant
Šumberová, Michaela ; Nábělek, Jakub (referee) ; Zemanová, Jana (advisor)
The Bachelor thesis focuses on the preparation and characterization of the extract of Gotu kola (Centella asiatica). The theoretical part summarizes commonly analyzed groups of biologically active compounds of herbs and introduces potential applications of the extract in food industry. Moreover, an overview of possibly used extraction methods and analytical methods for the evaluation of biologically active compounds of the extract are presented. As for the experiment, the extract of the fresh Centella asiatica herb was prepared by maceration in ethanol and then analyzed by three chosen methods. The total phenolic content of the extract analyzed by the Folin-Ciocalteu test was 0.74 ± 0.08 mgGAE·g-1. As for the quantification of antioxidant activity, the TEAC test was performed and the antioxidant activity of the extract was 289 ± 81 µg·ml-1. The volatiles present in the extract were identified by gas-chromatography mass-spectrometry in combination with solid-phase micro-extraction. Sesquiterpenoid hydrocarbons were the most dominant group of the extract, in which -farnesene (33.28 %), -caryophyllene (25.01 %), and -humulene (20.91 %) were the major compounds.
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Stability and properties of combined beverages and fruit concentrates
Klatová, Kamila ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
This diploma thesis deals with the stability and basic properties of combined beverages and fruit concentrates. The theoretical part describes the production and use of fruit concentrates. Furthermore, the work deals with anthocyanic pigments and phenolic substances. The principle and instrumentation of liquid chromatography and electron paramagnetic resonance were described. In the next subchapter, the methods of determination of total anthocyanins and phenolic substances were described. The experimental part of the thesis described the determination of soluble solids, viscosity and antioxidant activity. The total content of phenolic compounds were determined by the Folin-Ciocalteua method and the total anthocyanins were determined by the pH-differential method. In the samples were determined cyanidine-3-glucoside and cyanidin-3-galactoside by liquid chromatography.
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Selected nutritional parameters of some lesser known fruit
Diblíková, Michaela ; Hrstka, Miroslav (referee) ; Vespalcová, Milena (advisor)
Diploma thesis is focused on the chemical analysis of the juices of black, red and white currant and jostaberry (Ribes a Ribes x culverwellii). The theoretical part is focused to the definition of fruit, fruit importance in human nutrition, description of Ribes and Ribes x culverwellii genuses, active substances in the currants and the jostaberry, description of selected chemical parameters and the determination of some of them. The procedures of determining for the following chemical parameters are described in the experimental section: determination of reducing sugars, determination of total and soluble solids, formol number, pH, titratable acidity, determination of total phenols and anthocyanins and determination of vitamin C in two samples jostaberry, six varieties of black currants, one variety of white currant and two varieties of red currants. Based on the evaluation of the obtained results, the comparison was made with different varieties and the thesis that "overall comparison of the different varieties in the content of phenolic compounds, vitamin C and anthocyanins appears to be the most promising variety of blackcurrant demon. It should however be noted that the highest content of phenolics and anthocyanins were determined in jostaberry„ has been suggested.
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Use of secondary raw materials from wine production
Lajtman, Roman ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with using of grape pomace, waste from wine industry. It also deals with the determining of total phenolic substances in a grape pomace. The theoretical part focuses on the characteristic of grape, the chemical composition of wine, making of wine and mainly on use of secondary raw materials. It also describes phenolic substances, their division and finally something general about using experimental methods. In the experimental part a red grape pomace´s extraction was made. The extractions were made in different solvents, in a mixture ethanol-water (ratio 20:80; 40:60 and 60:40), also in a mixture glycerol-water (ratio 10:90; 20:80 and 40:60) and at the end in water. The extractions were made in a different time and the purpose was to optimize the extractions and to get the highest yield of phenolic substances, antioxidants. Time and economically side played an important role to find out and to choose the best solvent. In the results, as the best and the optimal extraction´s solvent on extraction of red grape pomace was chosen the mixture ethanol-water and ratio was 60:40. That mixture extracted the most phenolic substances and relatively in the shortest time. During the optimization of sample weight was found out that optimal sample weight is 4 g of grape pomace. At the end repeated extraction was made. It is obviously practically worthless. After second step of extraction, the concentration of phenolic substances is more than a half lower than at the first step.
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Extraction of bioactive substances from the pomace of red grapes
Jandrtová, Sabina ; Pořízka, Jaromír (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis deals with the research of chosen chemical characteristics in juice and in extracts of grapevine (Vitis vinifera L.). The theoretical part is divided into three parts. In the first part is described the botanical characteristic of grapevine, then its origin, morphology, chemical composition, species and uses. In the second part are characterized anthocyanin pigments, their occurrence and attributes. There are described methods of the investigation. In the third part are described extractions. The experimental part illustrates extractions of the pomace. The purpose of these extractions is to find out the total amount of anthocyanins and phenolics in the pomace, and which solvent gives the highest yield. Then the chemical characteristics, such as total and soluble solids, pH, the amount of titratable acids, reducing carbohydrates, phenolics and anthocyanins, are described in this section. All determinations are executed and results are compared among grapevine juice and two species (Cabernet Sauvignon and Zweigeltrebe). The most suitable solvent is selected a mixture of water and ethanol in a ratio 50:50. In the most effective hours are determined the chemical characteristics. The titratable acids are expressed as the amount of the tartaric acid. The amount of phenolics is expressed as gallic acid and the amount of anthocyanins as malvidin-3-glucoside.
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