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Determination of some nutrition factors in selected kinds of fruit
Smělá, Margita ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
Diploma thesis is concerned with determination of some nutrion factors and vitamin C in various cultivars of apples (Pirus Malus, L.) and quinces (Cydonia oblonga, Mill.). In theoretical part there are described general characterization in selected kinds of fruits, their medically significant sunstances and utilization of these fruits. Main focus is paid to vitamin C. There are described its chemical properties and effect for human health. Various methods for determination of some nutrion factors with focus on determination of vitamin C by high-performance liquid chromatography. In experimental part, total of 27 various cultivars of aplles and 16 various cultivars of quinces were analyzed. These cultivars are from grower station Faculty of garden of Mendel university. For determitation vitamin C was used by high-performance liquid chromatography. Vitamin C was determination as an ascorbic acid. Some nutrion factors were analyzed in experimental part. There were analyzed dry matter, total flavonoids, total phenolics and titratable acid in various cultivars of apples and quinces. There were compared of some various cultivars after representation and content of significant substances as result. The last part of thesis was sensory analysis of apples.
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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.
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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.
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Preparation and stability of core-shell type organic micro- and nanoparticles
Byrtusová, Dana ; Benešová, Pavla (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on possibilities of encapsulation polyphenolic compounds in core-shell type organic micro- and nanoparticles. The theoretical part is aimed at characterization of polyphenolic compounds, their biological effects and their possibilities of encapsulation into various types of particles. The experimental part deals with the content of polyphenolic compounds, flavonoids and anthocyanins in guarana, ginseng ang goji. Extracts from these samples were packed into liposomes and polysaccharide particles. Encapsulation´s effectiveness was determined spectrophotometrically. The stability of particles was monitored for size and stability by dynamic light scattering. The particles were exposed to the model body fluids and model food.
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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.
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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.
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Isolation and characterizaation of oil from some types of coffee
Vašků, Barbora ; Hoová, Julie (referee) ; Skoumalová, Petra (advisor)
Coffee, extract, oil, phenolic compounds, flavonoids, antioxidant capacity, SPF, critical wavelenght.
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Characterization of intermediates and waste products of some fermentation productions
Kilian, David ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
This bachcelor thesis was aimed on characterisation of intermediate and waste products of some fermentation productions. The theoretical part of this thesis is aiming on characterization of raw material and its fermentation, process of distillation, waste product and introduction of main active components of all these intermediates. In the experimental part were characterized intermediates and products regarding the contents of sugar, ethanol and polyphenol. All these extracts contain particular levels of polyphenol and sugar corresponding to individual phases of fruit distillates production. The chemical characteristics of extracts from different phases of fruit distillates production were compared. Parameters as total phenolics, flavonoids, glucose, fructose and ethanol were evaluated. Subsequently the changes between individual phases were described. In conclusion, a solution of further use of waste products formed during fruit fermentation process was suggested.
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Determination of Natural Compounds in Select Plant Materials and Less Obvious Kinds of Fruit
Hohnová, Barbora ; Márová, Ivana (referee) ; Ventura, Karel (referee) ; Omelková, Jiřina (advisor)
Flavonoids are natural compounds widely distributed in plant kingdom. They are inseparable from human diet because they showed a protective effect against cancer, stroke and coronary heart diseases related to their antioxidant properties. Therefore, rapid and efficient extraction procedure prior to chromatographic analysis is required. The liquid extraction at elevated temperature and pressure – Pressurized fluid extraction (PFE) and Pressurized hot water extraction (PHWE), present fast, effective and environmentally friendly extraction methods for the determination of flavonoids in plant materials. PFE and PHWE followed by reversed phase high-performance liquid chromatography with UV-visible detection have been utilized for the determination of a group of flavonoids (rutin, myricetin, quercetin, luteolin, apigenin and kaempferol) in the leaves and berries of less common plants. The matrices were extracted by methanol, ethanol and water at higher temperature 40-120 oC and pressure 15 MPa during 15 minutes. The obtained results were compared with conventional Soxhlet extraction and ultrasound-assisted extraction, the same solvents were used. The most effective extraction of selected flavonoids was achieved by PHWE. PFE showed the extraction yields comparable to those of the Soxhlet extraction, and the lowest extraction power was displayed by ultrasound-assisted extraction.
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Encapsulation of natural antioxidants
Štindlová, Jitka ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
In theoretical part of this diploma thesis the basic properties of antioxidants, especially anthocyanins and phenolic compounds are described, as well as the basic features and principles of free radicals formation. The theoretical part also describes some possible ways of encapsulation of antioxidants into polysaccharide and lipid particles. In the experimental part basic characteristics of extracts from selected lyophilized fruits and vegetables (carrots, apples and mixed berries) are described. As group parameters of plant extracts the total antioxidant activity, content of flavonoids and phenolics, carotenoids, anthocyanins and ascorbic acid were determined. In experimental part also various encapsulation techniques were tested, encapsulation effectiveness of each technique was evaluated and the stability and size of the created particles were determined. As the best encapsulation method in terms of encapsulation efficiency in most of samples/parameters ethanol injection was found. On the other hand the particles prepared by ethanol injection are relatively unstable in terms of zeta potential, which is followed by their tendency to aggregate. As the most stable particles prepared by thin layer evaporation (TLE) and reverse phase thin layer evaporation (RP-TLE) were evaluated. Particles prepared by TLE, RP-TLE and chitosan-alginate particles exhibited a negative charge, while particles prepared by ethanol injection stayed uncharged and chitosan particles have a positive charge.
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