National Repository of Grey Literature 102 records found  beginprevious21 - 30nextend  jump to record: Search took 0.01 seconds. 
Selected alcohol extracts of Sambucus nigra for use in cosmetology
Balonková, Daniela ; Doležalová Weissmannová, Helena (referee) ; Zemanová, Jana (advisor)
This thesis focuses on the preparation of selected alcohol extracts of elderberry and their use in cosmetology. In the theoretical part are described the botanical properties of the elderberry (Sambucus nigra). There are introduced and characterized bioactive compounds and toxic compounds contained in all vegetative parts of the plant. Attention is mostly focused on compounds with antioxidant properties. The theoretical part also contains a description of basic analytical methods, which are used in the practical part to characterize compounds contained in elder flowers. The practical part focuses on the optimization of the preparation of alcohol extracts with the aim to prepare the extract with the greatest possible content of polyphenols with respect to economy and production costs. Factors such as selection of the appropriate solvent, solvent to plant material ratio, solvent temperature, and extraction time are examined. Based on the total polyphenol concentration measured spectrophotometrically by the Folin-Ciocalteu method, the most suitable solvent is 60% ethanol, the ratio of plant material to solvent is 1:8, the laboratory temperature of solvent and the extraction time of 24 hours.Under these conditions, an ethanol extract is prepared, analyzed and determined selected properties, such as refractive index and density. Rutin, chlorogenic, caffeic and ferulic acids are identified by HPLC with a DAD detector. The pH value of alcohol extract is 5.743 ± 0.006, the refractive index is 1.365 ± 0.02 at 22.7 ° C and the density is 0.9288 gcm-3. By liquid chromatography the concentration of chlorogenic acids is quantified as 0.104 gl-1, caffeic acid as 0.086 gl-1 and ferulic acid as 0.060 gl-1. The extract is incorporated into cosmetic products, that are used in balneology. Prepared products are toilet soap and bath salt.
Evaluation of Physical and Chemical Parameters of Still Less Exploited Species of Small Fruit and Proposal of a New Soft Drink from this Fruit
Cetkovská, Jitka ; Krška,, Boris (referee) ; Barták,, Petr (referee) ; Omelková, Jiřina (advisor)
This thesis deals with still less expolited species of small fruit, evaluation of its physical and chemical parameters and proposal of a new soft drink from one of the studied species of furit. Firstly, for the characterisation of basic nutrition parameters (dry matter, content of organic acids and saccharides) and biologicaly active substances (vitamin C, anthocyanins and phenolic compounds) suitable titration, spectrophotometric, chromatographic and electrophoretic methods were chosen, optimized and validated. The sample preparation procedure was optimized as well. For three years (2010–2012) the content of listed parameters was monitored in some cultivars of five species of small fruit: in seven cultivars of sea buckthorn, in ten cultivars of cornelian cherry, in twelve cultivars of rowanberry, in two cultivars of chokeberry and in seventeen cultivars of elderberry. By means of Duncan’s test, analysis of principal components (PCA) and cluster analysis (CLU) the main differences between studied cultivars were observed mainly in sea buckthorn and rowanberry, where single cultivars were easily distinguishable from others on the basis of genetic origin. On the basis of comparison of determined parameters in studied species of fruit and with collaboration with fruit processing company the suitable species of fruit for commercial utilization was chosen – elderberry, as a important source of anthocyanins and phenolic compounds. A new soft drink as a proposal of utilization of this fruit was created – fruit juice or nectar with portion of elderberry juice. Mixed juices and nectars with various composition were prepared from elderberry and grape juice and the sensory analysis of these drinks was performed. The best evaluated were 100% fruit juices prepared with 30–50% portion of elderberry juice. The composition was jurally protected. On the basis of this protection the product consisted from 100% fruit juice with 10% of elderberry component mixed with apple and grape juice was introduced to the market by the fruit processing company.
Determination of selected parameters in foreign beers
Punčochářová, Lenka ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
The aim of this thesis is determination of selected polyphenols, organic acids and elements (major and minor) in a foreign beers. Production of malt, beer production, beer types and beer styles are described in the theoretical part. Also analytical methods of beer analysis such as high performance liquid chromatography, iont chromatography and inductively coupled plasma optical emission spectrometry are described. The Experimental part deals with preparation of samples and calibration solutions, setting devices up and analysis of foreign beers samples. There were analyzed 14 foreign beers of which 11 samples were top-fermented beers, 3 samples were bottom-fermented. Four samples were produced in Belgium, three in England, three in Germany, two in the US, one in Holland and one in Poland. The results give an overview of the contents of compounds in foreign beers.
Study of properties and effect of some natural antimicrobial substances
Horňáková, Nikola ; Kostovová, Iveta (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on the testing of natural antimicrobial substances of plant origin, dealing with their characterisation, their effect against the microorganisms, optimization of antimicrobial testing and increasing of efficiency of their active compounds. Theoretical part of this thesis describes a characterisation of used natural species, their important properties, spectrophotometrical methods applied in determination of active compounds, opportunities of stabilization of natural substances and various techniques of antimicrobial testing. In experimental part 8 kinds of tea and non-tea plants (Pai Mu Tan, Formosa Gunpowder, Gunpowder Black, Honeybush, Lapacho, Aspalathus linearis and Paullinia cupana) were used and combined with 6 herbal species (Syzygium aromaticum, Urtica dioica, Hippophae rhamnoides, Matricaria recutita, Plantago lanceolata and cinnamon), extracted by different solvents (water, ethanol and dimethyl sulfoxide). In these extracts amount of antioxidants and effect to three bacterial cultures (Escherichia coli, Micrococcus luteus and Serratia marcescens) were determined. To improve antimicrobial, antioxidant activity and stability aqueous tea extracts were encapsulated into liposomal particles.
Characterization of cereal products with fruit component for baby nutrition
Pražáková, Jana ; Lichnová, Andrea (referee) ; Márová, Ivana (advisor)
Present bachelor thesis deals with the characterization of milk cereal products intended for baby food. The theoretical part focuses on the morphology of cereal grains, fortification, an overwiev of supplementary components used to fortification and their properties. For the practical part eight kinds of cereal dairy products of three different producers were chosen. In these products total polyphenols, total flavonoids, reducing and total saccharides and proteins were analyzed. The highest level of polyphenols was measured in product Sunar multicereal. The highest amount of flavonoids (more than 50 % of total phenolics) was found in Nestle fruit product. The highest level of total and reducing saccharides contained Nestlé honey flavour. High amount of proteins was found in products Sunar with multicereal flavour and pears with biscuits. Using HPLC/UV-VIS analysis vitamins C and E were determined. The highest content of vitamin C contained Nestlé with cookie lavor, while high vitamin E level was found in Sunar pear flavor and biscuits. Using HPLC/RI individual saccharides were examined. In all products high amount of lactose was found, mainly in the products of Sunar. Nestlé products contained mostly glukose, while in products Hami sucrose was detected as the most abundant saccharide.
Preparation of some application formula of antimicrobial substances
Krempaský, Kamil ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The main aim of this study is to determine antimicrobial activity of herbal extracts and also encapsulate these extracts and lysozyme to liposomes. The extracts were prepared from above ground part of wormwood (Artemisia absinthium), aerial part of breckland thyme (Thymus serpyllum), the root of purple coneflower (Echinacea purpurea), liquorice (Glycyrrhiza glabra), corolla of pot marigold (Calendula officinalis) and berries of sea buckthorn (Hippophae rhamnoides). In all extracts antioxidant activity and the amount of total polyphenols and flavonoids was determined. All of these extracts and also lysozyme were used for encapsulation to liposomes. Prepared liposomes were then tested for their stability. Further, encapsulated as well as free extracts were tested for their antimicrobial activity on Escherichia coli, Serratia marcescens, Micrococcus luteus and Bacillus subtilis. Extract from Echinacea purpurea showed the highest antimicrobial activity.
Study of natural antimicrobial mixtures and their stabilization
Vejrostová, Petra ; Veselá, Mária (referee) ; Márová, Ivana (advisor)
Present diploma thesis is focused on natural antimicrobial substances. The aim of the experimental part of thesis was testing of antimicrobial activity of selected natural substances in free and encapsulated forms, preparation of particles and monitoring of their long-term stability. Various teas extracts (aqueous, ethanoic and DMSO) and aqueous herbs extracts were used as plant antimicrobial substances. Liposomes and chitosan particles with encapsulated aqueous teas extracts were prepared by ultrasonication. Encapsulation efficiency, size, stability and antioxidant activity for all particles were specified. Consequently, within a two months period, long-term stability for these particles was monitored. Spectrophotometric method for determining total polyphenols was used for evaluating encapsulation efficiency as well as for monitoring of long-term stability. The DLS method was used for determination of size and stability of particles. Antioxidation activity was monitored by using spectrophotometric method using ABTS. For testing antimicrobial activity of various types of teas, herbs extracts and their mixtures and combianitons with lysozyme and antibiotics, broth dilution methods were used while using both Gram positive and Gram negative bacterial test strains. Antimicrobial activity of prepared particles was also monitored, the antimicrobial activity was especially significant with the chitosan particles. Suitable combinations of natural substances whatever with antimicrobial or antioxidation effect either in free or encapsulated form could be used for applications for example in cosmetics industry, food processing or in medicine.
Monitoring the stability of the beer brewing process
Tichá, Anna ; Štursa, Václav (referee) ; Diviš, Pavel (advisor)
The bachelor thesis deals with the analysis of 3 samples of the same beer, brewed in different batches of the brewing process. The analyzed sample is Dalešická jedenáctka - light lager of 11% of the Stock Brewery Dalešice, a.s., which was taken directly from the lager tanks in the brewery. The aspect we have examined were total protein content, total carbohydrate content, maltose content, total polyphenol content and ethanol content. The Hartree-lowry method was used to analyzed the total protein content. Total carbohydrates were measured spectrophotometrically using anthrone reagent. The maltose content was analysed by HPLC with an ELSD detector. The total polyphenol content was analyzed by the Folin-Ciocaltau reagent method and measured spectrophotometrically. The ethanol content was analyzed on a HPLC using a refractometric detector. The aim of the work was to compare to what extent the process of beer production is stable and what parameters may change in the final product
Biological effects of various hemp fractions
Vacková, Hana ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
Cannabis is the only plant which contains cannabinoids and thanks to these compounds it has enormous potential. This thesis deals with the analysis of technical hemp. Effects of cannabinoids and methods used for cannabis analysis are discussed in the theoretical part. The experimental part includes spectrophotometric characterization of cannabis, it´s antimicrobial effects and thin layer chromatography analysis. Three sorts of Cannabis sativa L. were analyzed, namely Finola, Fedora and Kompolti. Firstly, the content of polyphenols, flavonoids and antioxidant activity in prepared tinctures were determined. Moreover, antimicrobial test were performed using disk test and turbidity determination. Gram-positive and Gram-negative bacteria and yeast organism were tested. It was found that cannabis tinctures possess good antimicrobial effects. Some of them are comparable with synthetic antibiotics. Finally, thin layer chromatography enabled visualization of cannabinoids in prepared tinctures.
Characterization of blackthorn products
Červinková, Zuzana ; Veselá, Mária (referee) ; Kovalčík, Adriána (advisor)
This bachelor thesis deals with the preparation and the chemical characterization of ethanolic extracts and products from the blackthorn (Prunus spinosa L.) fruit. The theoretical part of the work contains the characterization of the blackthorn and describes the chemical composition of the fruit. Furthermore, the theoretical part states possible effects and possible uses of the Prunus spinosa L. fruit in the food industry, folk medicine and pharmacy. The experimental part describes the preparation of the extracts (40% ethanol) and the products (i.e., homemade sloe wine and homemade blackthorn liqueur). The content of reducing sugars, polyphenols and flavonoids was quantified in samples of wine, liqueur, juice and ethanol extracts. Furthermore, the antioxidant activity of individual samples was determined. Two spectrophotometric methods for the determination of reducing sugars were used and compared, namely the Somogyi-Nelson (SN) assay and the 3,5-dinitrosalicylic acid (DNS) assay. The DNS assay provided slightly overestimated results, while the results from the SN assay were closer to the actual content of reducing sugars. Polyphenols and flavonoids are substances that have antioxidant properties. A strong correlation was observed between antioxidant activity and the concentration of flavonoids.

National Repository of Grey Literature : 102 records found   beginprevious21 - 30nextend  jump to record:
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