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The antioxidant activity of selected species of small fruit
Křenová, Alena ; Gregor,, Tomáš (referee) ; Diviš, Pavel (advisor)
This diploma´s thesis deals with the determination of total antioxidant activity of red and white gooseberries and red, white and black currants. There are available information about small fruits, an overview of natural and synthetic antioxidants and a summary of the methods to determine the total antioxidant activity in the theoretical part. Frozen fruit samples were provided by Research and Breeding Institute of Pomology Holovousy Ltd. in the project QI111A141 – Research of new technologies in the cultivation of gooseberries and currants with a focus on quality and use of fetuses (Ministry of Agriculture). The total antioxidant activity of red and white gooseberries and currants was measured by spectrophotometric methods using free radicals ABTS•+ and DPPH and was expressed as a Trolox equivalent. The total antioxidant activity of black currants was measured by electron paramagnetic resonance using free radicals ABTS•+ and DPPH and expressed as a TEACABTS and a TEACDPPH. There were measured 8 species of red gooseberries, 6 species of white gooseberries, 12 species of red currants, 6 species of white currants and 8 species of black currants in this thesis. The highest values of total antioxidant activity showed species of red and white gooseberries Alan, Karmen, Pax and Invicta and species of red and white currants Rovada, Orion and Olin. Among black currants, species Ometa and Ruben had the highest values of total antioxidant activity.
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Complex characterisation of gooseberry fruits
Rodzíková, Martina ; Vespalcová, Milena (referee) ; Vítová, Eva (advisor)
This thesis deals with the assessment of aroma active compounds in gooseberry and sensory analysis of it focusing on flavour. The theoretical part describes general characteristics, biological marks and properties of selected varieties, healing abilities, the active substances contained in gooseberry fruits and their use. The aim of the experimental part was to determine aroma-active substances contained in fruits of nineteen selected cultivars of gooseberry using SPME-GC-FID method. In total 45 volatile compounds were identified, among them 17 alcohols, 11 aldehydes, 6 ketones, 9 esters and 2 acids. For a better identification one sample (Captivátor variety) was also analysed using GC-MS with purge and trap extraction. Pentan-1-ol, hexanal, pentanal, ethylethanoate, ethylbutanoate, methylethanoate, methylbutanoate and ethanol were confirmed using mass spectra. Only several cultivars were selected for the assessment of overall sensory quality and palatability of fruits. Karmen and Remarka varieties were considered as the best samples by assessors.
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Elemental analysis of different kinds of small fruit
Štursa, Václav ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This diploma thesis deals with the elemental analysis of soft fruit species such as currants and gooseberries. The theoretical part contains botanical description of both species, then description of nutritional properties of the individual analyzed elements and ends with a list of analytical methods suitable for elemental analysis in the food science and with a description of preparation. The experimental part deals with sample preparation and its analysis afterwards with spectroscopic techniques. Samples of different varieties of gooseberries, black, red and white currant from “Výzkumný a šlechtitelský ústav ovocnářský v Holovousích, s.r.o.” have been used for the analysis. Samples were mineralized in concentrated HNO3 and analyzed by ICP-OES technique. Difference in resultant concentrations of the analyzed elements (Ca, Cu, Fe, K, Mg, Mn, Na, P, Zn) between individual varieties were statistically compared by Tukey’s multiple comparison method and results achieved have been as well compared with the results reported in available literature.
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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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Basic chemical characteristics of juices of selected white gooseberry varieties
Zelníčková, Jaroslava ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
Theoretical part of this bachelor thesis includes taxonomical classification of gooseberry, deals with biological characteristics, active substances contained in fruits of gooseberry and its using as well with description of the methods by research detection. In the experimental part primary nutritional parameters of chosen gooseberry species were analysed including orientation juice yield, soluble solids, pH, dry matter, titratable acids, formol number and reducing sugars. There were analysed following species of gooseberry: Reflamba, Mucurines, Rixanta, Veliš, Citronový obří, Darek, Prima, Invicta, Zlatý fík a Zebín. Individual species and cultivars were compared based on the results.
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The basic chemical parameters of berries from some gooseberry cultivars
Nguyen, Quynh Anh ; Vespalcová, Milena (referee) ; Hrstka, Miroslav (advisor)
This bachelor thesis deals with assessment of basic chemical parameters in berries of some gooseberry cultivars. In theoretical part the taxanomy classification of gooseberry and its botanical characteristics are mentioned. The history of breeding, appropriate conditions, including the most common diseases and pomology of each cultivars are also described. Next chapter is dedicated to the chemical composition of gooseberry. In experimental part some chosen chemical parameters (yield of juice, soluble dry matter content, dry matter general content, pH, titratable acidity, formol number and reducing saccharides content) of few gooseberry cultivars were determined.
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Elemental analysis of the different gooseberries varieties
Nývltová, Barbora ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This bachelor thesis describes and explores the elemental analysis of several new varieties of red and green gooseberries. The theoretical part deals with the history, taxonomy, cultivation and biological characteristics of gooseberry. The next part of the thesis is focus on the summary of nutritional parameters of the analyzed elements and it also describes the methods which characterize the analysis in the food use. The experimental part deals with the preparation of the sample, its subsequent decomposition by using wet way and of the actual analysis using the technique ICP-OES. The sample was provided by “Výzkumný a šlechtitelský ústav ovocnářský v Holovousích, s.r.o.”. The results of analyzed elements (Cu, Fe, Mg, Mn, P, Zn, Ca, K, Na) in the various varieties of gooseberry were further evaluated using statistical methods. These results were then compared with the available databases. The most promising in terms of the content of individual elements proved to be a variety of red gooseberry Rolonda and Jocheline, a variety of green gooseberry Invicta and Mucurines.
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Determination of selected nutritional parameters in the fruit of the plant genus Ribes
Ledvina, Vojtěch ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis focuses on the small fruit representatives from the plant genus Ribes L. - currant, gooseberry and jostaberry. The beginning of theoretical part describes history of cultivation and basic botanical description of individual cultivars. The next part describes important substances contained in fruit as well as their importance in human diet and it also describes some basic products made of the Ribes L. genus representatives. The final section of the theoretical part contains basic principal of determination of individual nutritional parameters. In the experimental part several nutritional parameters were determined including dry matter, soluble solids, pH, titratable acids, formol number, reducing sugars and total phenolics. Individual species and cultivars were compared based on the results.
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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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