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Vitamin C
Juráňová, Jana ; Hrstka, Miroslav (referee) ; Vespalcová, Milena (advisor)
The theme of this diploma thesis is an assessment of given nutritional parameters in selected kinds of lesser known fruits, specifically 10 varieties of sea buckthorn (Hippophae rhamnoides L.), 12 varieties of cornelian cherry (Cornus mas L.) and 6 varieties of blue honeysuckle (Lonicera caerulea var. kamtschatica). Harvests of two consecutive years (2011 and 2012) were analyzed in the case of blue honeysuckle. The theoretical part was focused on historical, morphological, taxonomic and nutritional aspects of individual plants and food or pharmaceutical utilization. The considerable part of the thesis is devoted to the characterization and the possibilities of determining the contained substances, namely ascorbic acid and polyphenolic compounds, especially anthocyanins. The content of the experimental part was a description of the methods and the results of the analysis of total solids, titratable acidity, total phenolics, total anthocyanins and ascorbic acid in fruits of the selected varieties of the above mentioned fruit species. Based on the measured results, the different varieties of fruits were compared to each other and evaluated.
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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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Analysis of selected nutritional parameters in the new varieties of gooseberries
Nováková, Jana ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
Diploma thesis deals with the new varieties of gooseberries. The theoretical part characterizes gooseberry from a biological point of view, what is the content of healthful nutrients and states food technology aspects. Furthermore, the theoretical part deals with the main parameters examined nutrition: vitamin C, anthokyanům and antioxidant activity. In the experimental part was measured both weight solids content and soluble solids. Vitamin C was measured by HPLC, anthocyanins using a pH differential method and for antioxidant activity determination was selected method by Kanedy known also as DPPH.
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Characterisation of chokeberry and saskatoon berry fruits
Burdějová, Lenka ; Omelka, Ladislav (referee) ; Vítová, Eva (advisor)
Diploma thesis deals with the characterization of chokeberry (Aronia melanocarpa) and saskatoon berry (Amelanchier alnifolia) fruits. The theoretical part focuses on the botanical classification, chemical composition, curative effects and the use of chokeberry and saskatoon berry in the food industry. Further, the attention is also devoted to a review of methods for the determination of important antioxidants, specialized on the determination of polyphenols, anthocyanins, ascorbic acid and total antioxidant activity. The experimental part of the work deals with the determination of selected parameters in different varieties of chokeberry and serviceberry, harvested in 2012 and 2013 using spectroscopic and chromatographic techniques with an emphasis on effect of solvent (50% ethanol, destilled water, DMSO). Specifically total content of polyphenols and anthocyanins, color characteristics using the CIE L*a*b* system and the ability of the sample to reduce the iron are determined using the UV-VIS-NIR spectroscopy. Further ascorbic acid concentration in individual extracts is quantified by High performance liquid chromatography coupled with a diode array detector and the total antioxidant activity is characterized by electron paramagnetic resonance involving •DPPH and ABTS•+ assays.
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Smart food polymer layers
Valíková, Michaela ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
Smart packaging represents a group of packaging with great potential when used in the food industry. Active packaging can have a positive effect on the condition of stored food and smart packaging can inform consumers about the condition of stored food. In the theoretical part, a search was made on the topic of packaging in the food industry, with emphasis on active and intelligent packaging, including the legislative framework. The substances from which smart packaging is made have been described. In the experimental part, partially water¬insoluble polymer layers were prepared from gelatin, glycerol, crosslinking agent and anthocyanin extract. Glutaraldehyde or tannic acid was used as a crosslinking agent. Anthocyanins were obtained by extraction from red cabbage. The total concentration of anthocyanins in the extract was determined by the difference method. For prepared layers, their water solubility was measured and the colour response to the pH environment was evaluated spectrophotometrically. The stability of the layers over time was also monitored. It was found that the prepared layers are able respond to changes in pH.
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Dyes of red and white wine cultivars
Peprná, Tereza ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
Theoretical part of this bachelor thesis contains informations about dyes of red and white grape species. At the beginning there is described component composition of grape berry. The biggest attention was paid to colour of red wine species. It deals with their common characterization, stabilization of their behaviour during production and storage wine. This work includes short recherche of their determination methods. Than there are mentioned colour of white wine cultivars. In another chapter there are described process of freeze drying otherwise lyophilization procedure. This method was used in experimental part while grape sample manufacturing. Grapes were immediately frozed on the dry ice after their separation. Skins were separated from pulp in nitrogen atmosphere and than these skins were lyophilizated.
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Changes of antioxidants in selected fruits during long-term freezing
Štindlová, Jitka ; Lichnová, Andrea (referee) ; Márová, Ivana (advisor)
In this bachelor thesis some low molecular weight antioxidants contained in strawberries, raspberries, blueberries and cranberries are described. In the theoretical part also general characteristics of these fruits are introduced. Experimental part was focused on analysis of the changes of selected antioxidant content in the fruits. These changes were monitored during storage in two different conditions – in refrigerator and in freezer. In refrigerator whole fruits were stored for 8 days. The experiment in the freezer was performed for 2 months and the fruits were stored in four different processed forms – as a whole fruit, whole fruit impregnated by sucrose solution, as a pulp and pulp mixed with sucrose. Antioxidant content in fruits was analyzed by HPLC and spectrophotometry. The highest total content of antioxidants was found in strawberries, while the lowest values were found in raspberries. During storage some part of original antioxidant content stayed conserved, the highest content was preserved in blueberries processed as a whole fruits and impregnated whole fruits.
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Characterization of minor fruit varieties in terms of use in the food industry
Jurečková, Zuzana ; Vítová, Eva (referee) ; Golian, Jozef (referee) ; Diviš, Pavel (advisor)
The thesis deals with one group of small fruits, the genus Ribes, ie currants, and gooseberries. It assesses their physical and chemical parameters with respect to the possibility of use in these properties for the design of a new type of product – beverages. Titration, spectrometric and other methods were used for the evaluation of these properties. A total of fifteen of these methods were available (total juice yield, juice pH, total dry matter, soluble fruit dry matter, titratable acidity, formolic number, reducing carbohydrate content, D-glucose, D-fructose and sucrose content, total polyphenolic substance content, anthocyanins, vitamin C and total antioxidant capacity) and a total of nine analytes (copper, iron, magnesium, phosphorus, zinc, manganese, potassium, calcium and sodium) were selected for the determination of mineral elements. For two years (harvest 2014 and 2015), these parameters were monitored for color variants of currants (white, red and black) and gooseberries (green-fruited, yellow-fruited and red-fruited). A total of six white varieties were tested in the group of currants - Olin, Jantar, Primus, Blanka, Viktoria and Orion, eleven varieties of red currants - Junnifer, Jesan, Detvan, Rovada, Rubigo, J.V.Tets, Tatran, Losan, Kozolupský raný, Stanca, NŠLS 11/6 and eleven varieties of black currant varieties - Ometa, Démon, Triton, Ben Hope, Ruben, Ben Gairm, Ben Lomond, Moravia, Ben Conan, Fokus and Ceres. A total of five varieties of green-fruited gooseberries were tested - Zebín, Mucurines, Rixanta, Rodnik and Prima. Yellow-fruited gooseberries were available in four varieties - Lemon Giant, Invicta, Golden Fig and Darek. The red-fruited gooseberries included varieties - Rolonda, Alan, Karat, Karmen, Krasnoslawjanskij, Himnomacki Rot, Remarka, Tamara and Black Neguš. Using Tukey's test, an analysis was performed and by scoring individual varieties based on the results of individual analyzes, a list of recommended varieties was compiled for further work on the development of a new beverage. Unfortunately, in 2015 there were very few fruits of green-fruited and yellow-fruited gooseberries, so it was decided that the volume of fruit will fall on the testing of bioactive substances. Therefore, at the end of the work, it is not possible to objectively evaluate these varieties of gooseberries in the whole range of analyzes. Therefore, the point evaluation of varieties was based on the averages of individual varieties. The red-fruited varieties were available in full, and therefore a full evaluation could take place. The most significant differences between red gooseberry varieties were in the content of bioactive substances (the content of polyphenolic substances, anthocyanin dyes, and vitamin C) and antioxidant capacity. These results were provided to the food subject, which continued to work with these values. Based on this project, utility model No. PUV 2016-33171 and the resulting combined drink based on wine and fruit juice were developed.
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The possibility of using of elderberry fruit pomace
Ondrušová, Pavlína ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
This diploma thesis concerns the determination of anthocyanin pigments in the elderberry pomace (Sambucus nigra L). The theoretical part describes in general the plant specification, its chemical composition, botanical characteristics and the possibility of utilization of elderberry in food processing industry and in pharmacy. However, the main concern of this thesis are the anthocyanins. This part is closely focused on chemical structure and factors that have significant influence over their stability. There are briefly summarized the positive effects of these colourants and their use in the food industry. In the experimental part, the elderberry juice and the extracts from the rhizomes were prepared. Two different solvents, a 1: 1 water / ethanol mixture and a mixture of water and methanol in the same ratio were used as extractors. To identify and quantify the dyes in the prepared samples, a chromatographic separation system (HPLC) with a Kinetex EVO C18 column and isocratic elution of the combined mobile phases of water of acetonitrile and formic acid was developed. The analysis only took 12 minutes. Two major dyes cyanidin-3-glucoside and cyanidin-3-sambubioside were identified and quantified by HPLC. The largest amount of anthocyanins was obtained by extracting mixture methanol / water (594.6 ± 0.42 mg.100 g-1). The content of anthocyanin dyes in dry extracts and juice was also determined by the often-used pH-differential method. Both results were compared. The HPLC method provided very accurate results against the less demanding pH-differential assay method, which proved to be suitable for the indicative measurement of anthocyanin content in real samples.
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Comparison of the fruits of some honeysuckle varieties in terms of content selected biologically active compounds
Veselý, Ondřej ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
This thesis is focused to the analysis of selected varieties of honeysuckle kamtschatica (Lonicera caerula var kamtschatica) and their comparison in terms of the content of biologically active substances. There were analysed only varieties grown in 2014. Theoretical part elaborates and characterized various parameters of biologically active compounds such as phenolic, anthocyanins and ascorbic acid and possibilities of their determination. Further it briefly surveys Kamchatka honeysuckle, its taxonomic and morphological properties and its nutritional properties. The experimental part of the work was focused on the description of the methods used for the analysis of biologically active substances and their analysis. Polyphenolic compounds and anthocyanin’s were determined spectrophotometrically and vitamin C was determined by high-performance liquid chromatography. The results and varieties were compared with each other. Overall, we can say that the variety with the highest content of all three analysed biologically active substances is a variety Valchová, which had the second highest content of polyphenolic compounds (546.3 mg · 100 g-1 fruits), the third highest contend of ascorbic acid (35.1 mg · 100 g-1 fruits) and the sixth highest content of anthocyanin (170.8 mg · 100 g-1 fruits)
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