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Determination of the effect of dog rose (Rosa canina L.) on the oxidative stability in fresh juices
Borová, Šárka ; Mikulíková, Renata (referee) ; Kovalčík, Adriána (advisor)
This bachelor thesis aimed to determine the content of bioactive substances and antioxidant activity in ethanolic extracts of rose hips fruits (Rosa Canina L.). This work verified the possibility of using the rosehip ethanolic extract as an antioxidant to inhibit the oxidation of fresh pear juice. The ethanolic extracts were prepared by extracting rose hips fruits in various ratios of fruits to the volume of 40% ethanol for 7-28 days. After determining the total content of carbohydrates, polyphenols, flavonoids and vitamin C, it was found that, in principle, the range of the defined substances increases with the ratio of rosehip fruit to the volume of ethanol solution as well as with the extraction time. Ethanol rosehip extracts have also been shown to possess significant-high antioxidant activity. The stabilizing effect of rosehip fruit extract against the oxidation of fresh pear juice was determined spectrophotometrically. It was found that rosehip fruit extracts could inhibit the oxidation of fresh pear juice and have the potential as a natural stabilizer of fresh fruit juices.
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Study of the presence of phenolic substances and their antioxidant activity in food products containing rosehip (Rosa canina L.)
Hronová, Vendula ; Mikulíková, Renata (referee) ; Kovalčík, Adriána (advisor)
This bachelor's thesis monitored the content of bioactive substances and antioxidant activity in the jams made of the fruit of rose hips (Rosa canina L.). The jams were sweetened with various sweeteners such as cane sugar, beet sugar, erythritol and stevia. Moreover, the rheological properties of jams were determined. The properties of home-made jams prepared from rosehip fruit were compared with the commercial jam. Another aim was to determine whether the by-products received after the production of jams could serve as beneficial sources of bioactive substances after the preparation of water extracts. The content of carbohydrates, polyphenols, flavonoids, and antioxidant activity were determined in jams and extracts spectrophotometrically. Next, the spectrophotometric detection of pectin, the chemical characterization of jams by infrared spectrometry, and the spectrophotometric determination of the jam colour were performed. The concentration of bioactive substances in jams was influenced by the geographical location and the time and weather conditions of harvest. The rheological properties and pectin content of the jams depended on the type of the used sweetener. The assessment of the water extracts prepared from the by-products after jam production and from the dried fruits of rosehip showed the high content of bioactive substances and high antioxidant activity in all tested extracts. The presented work points out that it is possible to prepare jams with superfood properties from the fruit of rose hips and extracts with high antioxidant activity.
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Bioactive compounds of fennel
Nentvichová, Aneta ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this bachelor thesis is to study the bioactive substances contained in fennel, to determine the content of polyphenols, flavonoids and to investigate the antioxidant and antimicrobial activity in aqueous and ethanol extracts of fennel. The theoretical part discusses the characteristics of fennel, its classification in the system, its use and especially the bioactive substances contained in it. The experimental part is divided into two sections, where the first part focuses on spectrophotometric determination of polyphenols, flavonoids and antioxidant activities. In the second part the antimicrobial effects of prepared extracts of fennel were examined. Two microorganisms Serratia marcescens and Bacillus cereus were exposed to the said extracts. Antioxidant activity and relatively high content of polyphenols and flavonoids were found in the extracts in the first experimental part. The second experimental part proved that the antimicrobial effect of the extracts was very low, in most cases almost negligible. Ethanol extracts showed higher antimicrobial activity, while hot water extracts found to support the growth of Bacillus cereus.
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Účinky rostlinných produktů na růst, stravitelnost, složení těla, imunitní a stresovou reakci u ryb
ZARE, Mahyar
The plant powders and extracts contain bioactive compounds, including phenolic compounds, proteins, vitamins, and minerals. These compounds have been shown to possess antistress, antiviral, antibacterial, and antifungal effects on fish. Nettle has been extensively studied in mammalian medicine, but its effects on aquaculture species have not been well documented. Recent studies have demonstrated the positive impact of nettle on the growth performance, hematology, blood biochemistry, immune system, and pathogens resistance of fish species. Nettle leaf powder at a rate of 30 g/kg feed, improved the final body weight (FBW), weight gain (WG), weight gain percent% (WG%), specific growth rate (SGR%), and increased whole-body proximate protein and ash content while reducing whole-body proximate fat rainbow trout (Oncorhynchus mykiss) fingerlings. Tarragon leaf powder at a rate of 30 g/kg feed, significantly increased the haematocrit% (Hct%) and leukocyte count. The combination of 10 g/kg feed nettle leaf powder and 10 g/kg feed tarragon leaf powder resulted in the highest levels of erythrocyte count and haemoglobin (Hb). Nettle leaf powder at 30 g/kg feed, tarragon leaf powder at 30 g/kg feed, and a combination of 10 g/kg feed nettle leaf powder and 10 g/kg feed tarragon leaf powder significantly increased albumin levels in blood serum. Tarragon leaf powder at 10 g/kg feed showed the highest blood serum lysozyme enzyme activity compared to the control. Blood serum total immunoglobulin and total protein levels were significantly associated with nettle leaf powder at 30 g/kg feed. The study confirms the positive effects of these additives on growth performance, whole body proximate composition, immunological, haematological, and selected blood serum biochemical factors. Different levels of garlic powder did not significantly affect growth performance and somatic indices in European perch (Perca fluviatilis). However, adding 30 g/kg feed garlic powder resulted in a significantly higher level of whole-body proximate protein. Both 10 g/kg feed and 30 g/kg feed garlic powder showed significantly higher fat digestibility than the control and 20 g/kg feed garlic powder groups. The 20 g/kg feed garlic powder diet resulted in significantly higher erythrocyte and leukocyte count. Furthermore, all garlic groups had significantly lower blood serum cholesterol levels compared to the control. Garlic powder at level 30 g/kg feed improved European perch's resistance against high density and net handling stress, as well as their haematological and immunological parameters. Immediately after stress, the level of cortisol in all garlic-fed groups was significantly higher than in the control group, and there was no significant difference in glucose levels among the groups. However, after 24 hours, the levels of both cortisol and glucose were lower in all garlic-fed groups compared to the control group significantly. Garlic powder at a level of 10 g/kg feed improved apparent fat digestibility, whole body proximate protein, hematological parameters, immunological parameters, and increased resistance in high density and net handling stress. Overall, garlic powder could be considered as a potential dietary supplement for managing stress in European perch, however, further research is needed to determine the optimal dosage and long-term effects. Results of present thesis suggest that the use of natural feed phyto-additives could be a potential solution to address health issues in aquaculture, leading to more sustainable and efficient food production.
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Biologically active compounds of selected model trematodes
Kurečka, Martin ; Kameník, Zdeněk (advisor) ; Mikeš, Libor (referee)
Trematoda are parasites known for their ability to manipulate their host for survival and reproduction. They have complex life cycles with the intermediate host represented by mollusks and the definitive host, represented by vertebrates. This work focuses on three medically important genera of trematodes: Schistosoma, Fasciola and Opisthorchis. The aim of this work is to summarize biologically active low molecular weight substances that parasites modulate or produce in order to manipulate their host. The result of the work is a literature research of a comparative change in the concentration of metabolites of infected and uninfected trematode hosts with a focus on the analytical method used. Metabolomics deals with a comprehensive analysis of the metabolism of biological samples. It uses spectrometric analytical methods such as nuclear magnetic resonance and mass spectrometry combined with gas or liquid chromatography. Part of the work is also a summary of the importance, development and perspectives of metabolic profiling in parasitology. Current research in this area focuses mainly on vertebrate hosts. In addition, for vertebrate hosts, the sum of studied substances is still much broader than that in intermediate hosts. In intermediate host studies also focus on different types of substances,...
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Study of the presence of phenolic substances and their antioxidant activity in food products containing rosehip (Rosa canina L.)
Hronová, Vendula ; Mikulíková, Renata (referee) ; Kovalčík, Adriána (advisor)
This bachelor's thesis monitored the content of bioactive substances and antioxidant activity in the jams made of the fruit of rose hips (Rosa canina L.). The jams were sweetened with various sweeteners such as cane sugar, beet sugar, erythritol and stevia. Moreover, the rheological properties of jams were determined. The properties of home-made jams prepared from rosehip fruit were compared with the commercial jam. Another aim was to determine whether the by-products received after the production of jams could serve as beneficial sources of bioactive substances after the preparation of water extracts. The content of carbohydrates, polyphenols, flavonoids, and antioxidant activity were determined in jams and extracts spectrophotometrically. Next, the spectrophotometric detection of pectin, the chemical characterization of jams by infrared spectrometry, and the spectrophotometric determination of the jam colour were performed. The concentration of bioactive substances in jams was influenced by the geographical location and the time and weather conditions of harvest. The rheological properties and pectin content of the jams depended on the type of the used sweetener. The assessment of the water extracts prepared from the by-products after jam production and from the dried fruits of rosehip showed the high content of bioactive substances and high antioxidant activity in all tested extracts. The presented work points out that it is possible to prepare jams with superfood properties from the fruit of rose hips and extracts with high antioxidant activity.
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Determination of the effect of dog rose (Rosa canina L.) on the oxidative stability in fresh juices
Borová, Šárka ; Mikulíková, Renata (referee) ; Kovalčík, Adriána (advisor)
This bachelor thesis aimed to determine the content of bioactive substances and antioxidant activity in ethanolic extracts of rose hips fruits (Rosa Canina L.). This work verified the possibility of using the rosehip ethanolic extract as an antioxidant to inhibit the oxidation of fresh pear juice. The ethanolic extracts were prepared by extracting rose hips fruits in various ratios of fruits to the volume of 40% ethanol for 7-28 days. After determining the total content of carbohydrates, polyphenols, flavonoids and vitamin C, it was found that, in principle, the range of the defined substances increases with the ratio of rosehip fruit to the volume of ethanol solution as well as with the extraction time. Ethanol rosehip extracts have also been shown to possess significant-high antioxidant activity. The stabilizing effect of rosehip fruit extract against the oxidation of fresh pear juice was determined spectrophotometrically. It was found that rosehip fruit extracts could inhibit the oxidation of fresh pear juice and have the potential as a natural stabilizer of fresh fruit juices.
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Analysis of streptomycete isolates carrying a cyclizing aminolevulinate synthase gene
Rašmanová, Petra ; Petříčková, Kateřina (advisor) ; Felsberg, Jurgen (referee)
Streptomyces bacteria are well-known producents of many bioactive metabolites. Its secondary metabolism is a source of many important groups of active compounds that are recently investigated by means of many new methods based on bioinformatic analyses of genome data, modern LC-MS techniques, and metabolic modeling methods. This thesis originates from the genetic screening for a specific gene (als) for cyclizing 5-aminolevulinate synthase. Based on earlier studies, we consider this gene as a genetic tag of the producers of secondary metabolites containing the C5N unit (2-amino-3-hydroxycyklopent- 2-enon). Such metabolites include several groups with variable structures and biological activities, which include manumycins as well. Manumycins are small polyketides with a weak antibiotic aktivity, especially against gram-positive bacteria. However, its cancerostatic and anti-inflammatory effects are of greater importance. Streptomyces monomycini BCCO10 1552 and Streptomyces capoamus BCCO10 1636 strains were found positive for the presence of the als gene in the targeted genetic screening. By the als phylogeny, they cluster near the producents of manumycin compounds. This thesis aimed to determine whether these new natural isolates produce any compounds containing C5N unit, and to characterize them in...
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Chemical and biochemical transformation of bioactive compounds
Šimášková, Ema ; Sokolová, Romana (advisor) ; Martínková, Markéta (referee)
Xenobiotics, such as pharmaceuticals, food additives, environmental pollutants, and dietary bioactive compounds in organism are metabolized by various enzymes, resulting in their bioactivation or detoxification. Identification of structure of resulting metabolites is important for their detection in bodily fluids and tissues for diagnostic and forensic purposes. This thesis reviews known biochemical processes and enzymes involved in xenobiotic metabolism, including cytochromes 450 (CYP) and flavine monooxygenases (FMO). Given that biochemical reactions are to a major extent composed of electron-transfer reactions (i.e. oxidation and reduction), the thesis includes a section dealing with the practical approaches to determination of the oxidative or reductive mechanism of bioactive compounds.
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Bioactive compounds of fennel
Nentvichová, Aneta ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this bachelor thesis is to study the bioactive substances contained in fennel, to determine the content of polyphenols, flavonoids and to investigate the antioxidant and antimicrobial activity in aqueous and ethanol extracts of fennel. The theoretical part discusses the characteristics of fennel, its classification in the system, its use and especially the bioactive substances contained in it. The experimental part is divided into two sections, where the first part focuses on spectrophotometric determination of polyphenols, flavonoids and antioxidant activities. In the second part the antimicrobial effects of prepared extracts of fennel were examined. Two microorganisms Serratia marcescens and Bacillus cereus were exposed to the said extracts. Antioxidant activity and relatively high content of polyphenols and flavonoids were found in the extracts in the first experimental part. The second experimental part proved that the antimicrobial effect of the extracts was very low, in most cases almost negligible. Ethanol extracts showed higher antimicrobial activity, while hot water extracts found to support the growth of Bacillus cereus.
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