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Study of Allelopathic Effects of Common Millet on Other Plants
NWAJEI, Lucky
Proso millet (Panicum miliaceum) is an important source of energy and protein for people and as well animals. At present, there are practically no data available on the allelopathic effect of proso millet. The aim of the work was to evaluate the alle-lopathic effects of common millet on selected crops and to suggest the possibility of using the acquired knowledge. Laboratory experiments included evaluation of the effect of extracts from plant parts of millet and millet seeds on seed germina-tion and growth of selected plant species, as well as evaluation of autotoxicity of millet extracts, evaluation of the effect of different densities of millet seeds on allelopathic activity and stability of millet allelochemicals. The most effective extract inhibiting the growth of selected plants was the extract from young millet plants. However, millet allelochemicals do not seem to be suitable for weed control due to their low stability.
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Bacterial cellulose based facial mask with antioxidant property
Borová, Šárka ; Hoová, Julie (referee) ; Kovalčík, Adriána (advisor)
This final thesis deals with the preparation of a cosmetic facial mask based on bacterial cellulose. The motivation of this work was to prepare a cosmetic mask with antioxidant properties. To obtain bioactive substances with antioxidant activity, extracts from the rosehip fruits (Rosa Canina L.) with different weight dosages of rosehips and different preservatives were prepared. These rosehip extracts were subjected to spectrophotometric methods, thanks to which the total contents of polyphenols, flavonoids and total antioxidant activity were determined. It was proven that the content of the determined substances increases with the proportion of weighted rose hips and the highest contents of antioxidant substances were measured in extracts with a weight of 25 g of rose hips. Subsequently, these selected extracts were modified into several samples of bacterial cellulose. After the modification of the substances, it was demonstrated that bacterial cellulose is a suitable material for absorbing bioactive substances into the structure of individual analyzed samples. It was found that bacterial celluloses in the form of hydrogel and lyophilized bacterial cellulose were able to absorb the largest amount, of bioactive substances with antioxidant properties. On the other hand, the samples of dry bacterial cellulose and bacterial cellulose with an alginate component absorbed active substances the least. Furthermore, analysis using a Visioscope device revealed that the facial cosmetic mask based on bacterial cellulose in the form of hydrogel could potentially have not only antioxidant but also hydrating effects on the skin.
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Sledování fermentability sladin u vybraných druhů sladů
Zárubová, Emílie
In my diploma thesis on the topic “Monitoring the fermentability of worts for selected types of malt” has been processed information on the fermentabilitity of worts, the degree of fermentation, extractive substances and the factors that affect them. Furthermore, the thesis processes themes, which deals with malt, its production, requirements for malt and especially types of malt. Information is included not only conventional barley malt, but also on some less common types of malt. The first half of the diploma thesis processed this information on a theoretical level. The second half of the diploma thesis is focused on experimental activites related to the production of malts, worts and subsequent fermentation of the worts. For the production of the worts were used barley, wheat, oat, rye, corn and millet malt. The amount of extractives before fermentation, after fermentation and the amount of alcohol were determined for individual worts. Based on the difference between the extract before fermentation and after fermentation, the fermentability of worts produced from individual types of malts was determined. The results obtained are compared with those already known and with those obtained with conventional barley malt. According to the results, wort made from wheat malt shows the best fermentability. Wort made from barley malt shows the second best fermentability. Furthermore follow rye wort, oat wort, wort made from millet malt and the wort from corn malt shows the worst fermentability.
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Colorant properties and stability of Reynoutria pigments
DVOŘÁK, Vojtěch
This bachelor thesis is focused on invasive species of the genus Reynoutria, specifically on obtaining color extracts from their rhoots and subsequent evaluation of their color properties under various environmental conditions in laboratory conditions. The color properties of extract L, a, b, Cab, h and Eab were evaluated using a colorimeter. The extracts were obtained with 96°C warm water, cold water and 100% ethanol from dried and fresh material. The dye content in rhizomes and stems of Reynoutria japonica and Reynoutria sachalinesis was evaluated based on the total The roots of Reynoutria japonica and Reynoutria sachalinesis can be used as a source of yellow to red-violet dye. For the preparation of the extract, dried roots can be recommended at an extraction ratio of 3 g per 1 liter of water and extraction at 95 ° C for 1 hour. The information obtained can potentially be used in the application of dyes in industry or, after verification of health safety, also in the food industry.
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Iron-chelating properties of fruit extracts of various elderberries
Gorová, Barbora ; Mladěnka, Přemysl (advisor) ; Kašparová, Marie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Barbora Gorová Supervisor: Assoc Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of thesis: Iron-chelating properties of fruit extracts of various elderberries Inorganic iron is the major food source of iron in humans. It plays role in many biochemical reactions. Thus, iron metabolism disorders can lead to different diseases associated with lack of iron or iron overload. One of the possible treatment modalities of the latter represents the administration of iron chelators. Elderberry, Sambucus nigra L. (Adoxaceae), has been used in traditional medicine. The fruits of elderberry are a rich source of cyanidin-based anthocyanins as the main component. There are important differences, both in chemical and physical properties between several cultivars of elderberry. Anthocyanins might interact with metals in the gastrointestinal tract by formation of chelates. However, data on metal interactions with anthocyanins are sparse. The main aim of this study was to perform the analysis of interaction of iron with elderberry fruit extracts as a rich and cheap source of anthocyanins with cyanidin as the aglycon. In this in vitro study ten elderberry fruit exctracts were tested for iron chelating activities...
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Determination of volatile substances of natural extracts intended for cosmetic application
Paskevych, Olha ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
Tato bakalářská práce je soustředěná na zkoumaní přírodních komerčně dostupných extraktů, které se používají do přírodní kosmetiky. Literární rešerše byla zaměřena na téma obsahu těkavých látek v přírodních extraktech používaných v kosmetice, jejich charakterizace a možnosti stanovení, problematika výskytu alergenů v přírodní kosmetice. Na základě tohoto přehledu byla navržena optimální metoda pro analýzu vzorků přírodních extraktů s přihlédnutím k dostupné analytické instrumentaci. Následující výtažky byly studovány se zaměřením na kvalitativní stanovení: mandle, aloe vera, hřebíček, Etiopská káva, zázvor, cibule.
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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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Produkce alelopatických látek u vybraných bylin a jejich biologická účinnost
Nováková, Eliška
The thesis is focused on the study of allelopathy and allelopathic effects of Ambrosia artemisiifolia and Festuca rubra on selected species of herbs. The first theoretical part describes plants relationships and available information about allelopathy. The second part deals with the influence of Ambrosia artemisiifolia on the growth of Plantago lanceolata, Lotus corniculatus, Arrhenatherum elatius, Festuca rubra, Phacelia tanacetifolia and Pisum sativum in outdoor conditions in different cultivation substrates. The effect of extracts from roots of Festuca rubra and synthetic m-tyrosine on the germination of seeds Ambrosia artemisiifolia was evaluated. The obtained results confirmed the effect of Ambrosia artemisiifolia on the growth of the studied plants and the effect of the tested solutions on germination seeds of Ambrosia.
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Možnosti chmelení piva chmelovými extrakty a výrobky z chmele
Tichá, Kateřina
The aim of this thesis is to summarize the options of hop products leaded by hop extracts. The literature research focuses on chemical composition of hop, key transformation of hop bitter acids used in the brewing industry and also describes the technology of production of individual hop preparations and possibility of their application. The next part summarizes the beer production process including associated mikrobiology, which is an importand part of all stages of beer production. The experimental part describes production of six variations of beer chosen from different hop products, their chemical analysis and sensory evaluation. The results of the tests are evaluated statistically and are compared with each other at the end of the thesis.
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Characterization of edible films with the potential usage in food packaging
Jančíková, Simona ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
In the last years, the edible packaging has been gaining popularity due to the potential usage as the packaging for food instead of synthetic materials. The edible packaging can positively affect the packaged food by the active properties or due to its intelligent properties can monitor the changes in food. In theory, the legislation about the packaging of food and edible packaging was described. The substances for edible films preparation and additives, which can improve the properties of the edible films, were described too. In this part, the undesirable microorganisms occur in food and the chapters about active and intelligent properties of the edible films were summarized. The main aim of the thesis was the practical preparation of edible packaging/films made from furcellaran, gelatin hydrolysate with the addition of water dried or fresh rosemary extracts in concentrations 5 %, 10 %, and 20 %. In the experimental part, the physical analysis was done – textural parameters such as tensile strength and elongation at break, water content, and thickness. In the chemical analysis the total polyphenols content, determination of polyphenols by HPLC, antioxidant activity, optical properties and antimicrobial activity of the prepared edible films were done. There were found out, that the total polyphenols content and antioxidant activity were the highest in the 20%DR (TPC: 6,79 ± 0,06 mg gallic acid/g; DPPH: 87,84 ± 0,07 %). Also, the 20%DR and 20%FR changed color in different pH (3 and 12). The antimicrobial activity was negative. The thesis showed that the addition of natural extracts to edible films can increase the polyphenols content and they can also work as the UV protector.
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