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Determination of toxic and essential elements in plants
Filipčíková, Marcela ; Vespalcová, Milena (referee) ; Vitoulová, Eva (advisor)
The aim of diploma thesis is occurrence of toxic and essential elements in vegetables and fruit, especially in fruity baby food. The diploma thesis also dedicates processing of vegetables and fruit for production of baby food. Attention is direct to monitoring of baby food quality in the analytical aspects and also to legislative that is in this area. Samples for analysis are prepared using microwave mineralization and ICP-MS for detection. This is described in the experimental part of the diploma thesis.
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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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Influence of matrix type on the authentication of foodstuffs containing fruits
Kopková, Pavlína ; Strečanská, Paulína (referee) ; Fialová, Lenka (advisor)
Certain types of food, mainly the more expensive ones, are often adulterated to reduce their manufacturing price. However, this reduces their quality and can also have a negative impact on the health of the consumer. Children's fruit products are also targeted by fraudulent producers, where the declared fruit is most often replaced by a cheaper version. This work focuses on the detection of adulterated foods using various analytical methods, in particular PCR. The theoretical part focuses on the issue of food adulteration, the analytical methods used for detecting adulteration, and also on mango and banana which are determined in this work. The aim of this thesis was to determine what effect the type of matrix has on the determination of fruit components in food by PCR. Three types of matrix were used for this purpose - fruit puree, smoothie, and bars. An important task was to optimize the DNA isolation to achieve adequate purity and concentration of DNA. Then, the amplifiability of the obtained DNA was verified. The DNA isolates were then analyzed by multiplex PCR with primers specific for mango and banana. The results were verified by agarose gel electrophoresis. Subsequently, it was possible to determine that the fruit component in bars and fresh smoothies was the most easily analyzed by PCR and, on the contrary, the determination was problematic for puree. The instrumental part was focused on the determination of phenolic compounds in the products by HPLC. For this purpose, optimization of the extraction of phenolic compounds was necessary. This method was able to detect the presence of mangoes in all samples.
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Elemental analysis of different currants varieties
Kovaříková, Tereza ; Divišová, Radka (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with the elemental analysis of different varieties of red (Ribes rubrum), white (Ribes vulgare) and black currant (Ribes nigrum). The theoretical part contains botanical description of each variety of this small fruit, then description of analyzed elements and their function in human metabolism. Then there are described analytical methods suitable for elemental analysis in food. The experimental part is focused on the preparation of sample and its subsequent analysis by spectroscopic teqniques. All of the currant samples were given by Research and breeding institute of pomology Holovousy L.td. All the samples were mineralized by the wet ashing in concentrated HNO3 and analyzed by the ICP–OES teqnique. Final concentrations of each elements (Na, K, Ca, Mg, P, Fe, Zn, Cu, Mn) were stastistically compared by Tukey’s multiple comparation method and then have been compared with the results reported in literature.
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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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Detection of selected fruit species in plant-based foodstuffs through instrumental analysis and methods of molecular biology
Ondruch, Petr ; Langová, Denisa (referee) ; Fialová, Lenka (advisor)
Food is often subject to adulteration, including fruit products containing strawberries. This work deals with the detection of strawberries in model and real fruit products, so that possible falsification can be detected. The aim of the work was the preparation of model and real fruit products, their analysis using selected instrumental and molecular-biological methods and mutual comparison of the results of these methods. Model mixtures of fruit products were prepared and commercial ones were purchased. The content of polyphenols and flavonoids was determined by UV-VIS spectrophotometry, which were characterized in more detail by HPLC. DNA was isolated from the fruit purees, suitable primers confirmed the amplifiability and formation of a specific product for strawberry, and this product was verified by electrophoretic control. In the instrumental part, certain substances were detected by extraction from model and commercial mixtures and the HPLC method, and the amount of selected substances was determined. The lowest amount of strawberry DNA that could be detected by selected primers in the PCR method was 0.7 ng /µl, in commercial mixtures this DNA could not be detected. In the HPLC method, the strawberry was detected in all samples by focusing on a particular fingerprint and the amount of pelargonidin-3-glucoside in the samples. The instrumental method can be considered more suitable in this case.
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Design of juicer
Michalicová, Anežka ; Rubínová, Dana (referee) ; Tomášková, Veronika (advisor)
This bachelor's thesis deals with the analysis and afterwards design of a juicer. First part is devoted to an overview of the history of juicers then it continues in technical analysis of the product and further analysis of juicers available on the current market. Following chapters focus on my specific design proposal and the solutions it delivers. The output of the thesis is textual analysis, mock-up model and a poster.
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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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Changes of enzyme activities in fruits during long-term storage
Ferdová, Jitka ; Melounová,, Jitka (referee) ; Márová, Ivana (advisor)
This study is focused on study of changes of enzyme and low-molecular weight antioxidants in different fruits during long-term storage. In theoretical part individual low-molecular weight antioxidants and enzymes are described. The main causes of fruit decay and some possibilities of fruit preservation and storage are summarized. As biological material some common fruits were chosen - green and red apples, peaches, plums and white grapes. The fruits were stored in laboratory, cellar, in refrigerator and in freezer. In freezing experiments some ways of fruit preparation and processing were tested and their influence on fruit antioxidant status was compared. Shortened storage experiment was applied on blueberries, cranberries, raspberries and strawberries too. In fruits some group parameters – total antioxidant status, dry mass content, ascorbate level, total flavonoids and total phenolics were analyzed spectrophotometrically. Individual flavonoids and phenolics were determined by RP-HPLC/UV-VIS and on-line LC/PDA/ESI-MS. Antioxidant enzyme activities (superoxide dismutase SOD, catalase CAT, polyphenol oxidase PPO and lipoxygenase LOX) were measured by spectrophotometry. The surface microscopy and cultivation of moulds from fruit surface were performed too. Influence of storage conditions on biological activities is dependent on fruit sort. Freezing is the most suitable procedure for long-term storage without significant changes of active substance content. Long-term storage in controlled temperature conditions and/or atmosphere is usable for fruits with longer storage period. In these fruits stabile levels of antioxidant enzymes are stored for relatively long time. Some of enzymes act synergistically. Enzyme activities differed according to storage phase; at the beginning mainly high SOD and LOX activities were observed. CAT and PPO are probably activated as defence systems in rippened and/or damaged fruits. Levels of total as well as individual low molecular weight antioxidants varied during storage in all sorts, generally, increased course with longer storage period can be observed.
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Evaluation of a micromethod for isolation of DNA from plant leaf, fruit and fruit products
Balažovičová, Nikola ; Rittich, Bohuslav (referee) ; Kovařík, Aleš (advisor)
The thesis has been focused on testing of micromethod of DNA isolation from leaves, fruits and fruit products. Jams were selected for the analysis of plant DNA in technologically processed foods. Plant leaves, fruits, and jams were homogenized using plastic copist in a lysis buffer containing 2% cetyltrimethylammonium bromide (CTAB) with 2.5M sodium chloride (NaCl). Microisolation of plant DNA was performed using poly(hydroxyethylmethacrylate-co-glycidylmethacrylate) – P(HEMA-co-GMA)microparticles. Isolated the DNA concentration and purity were assessed by UV light aborbance using a spectrophotometer. After that, amplification of the DNA was tested in PCR. Primers specific for plant ribosomal DNA: 18S_for a 5,8S_rev (PCR product - 700bp), 26S_for a 26S_rev (PCR product - 220 bp), 18S_for a 18¬S_rev (PCR product - 263 bp) were used. The PCR conditions were optimized and the effect of the amplicon length on its detection was followed. PCR products were detected by agarose gel electrophoresis. It was shown that DNA isolated from almost all of leaves using magnetic particles was in PCR-ready quality in contrary to the fruits. DNA amplified in PCR with primers giving short PCR products was isolated from almost all tested jams. The method must be optimalised, yet.
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