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Preparation and characterization of nanoparticles with encapsulated antimicrobial component
Dohnalová, Marie ; Strečanská, Paulína (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on the preparation and characterization of particles with encapsulated natural substances with antioxidant and antimicrobial properties. Selected antioxidants were anthocyanins, eugenol and vitamin E, as one of the most powerful antioxidants. At the same time, antimicrobial agents were chosen, in this case eugenol. In the theoretical part, individual active substances, materials for the preparation of particles, methods of their preparation were characterized and the principle of determining the safety of used materials. In the experimental part, selected active substances were characterized and the preparation of particles was optimized. Two types of liposomes were prepared, for which the encapsulation efficiency, size and stability were determined. Also prepared aqueous extracts of blueberries and blackberries were prepared, for which total anthocyanin content has been determined. The extracted substances from the plant material were encapsulated into alginate particles. Furthermore, the gradual release of active substances from particles into model environments using a spectrophotometer was determined. During the gradual release of active substances from the particles, the antioxidant effect was also monitored, in which it was possible to observe a decrease with the passage of time. The antimicrobial effect of active substances and liposomes against model microorganisms Escherichia coli and Micrococcus luteus was also tested. Cytotoxicity tests on human keratinocytes were performed on selected active substances, extracts and prepared nanoparticles, where it was proven that the selected materials are non-cytotoxic. Finally, a proposal for a possible application form in the form of an alginate hydrogel was created.
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Optimization of Combined Chitosan Particles and their Characterization for Application Use
Netopilík, Tibor ; Hudečková, Helena (referee) ; Márová, Ivana (advisor)
The thesis deals with the preparation and characterization of nanoparticles for cosmetic and food applications. The thesis explores various methods of preparing nanoparticles, including liposomes and chitosomes, and analyses their properties and stability in different model environments. The experimental part includes the determination of the encapsulation efficiency of different vitamins by HPLC and UV-VIS spectrophotometry. Results show the influence of various factors such as time, type of environment and method of preparation on stability and efficiency of the nanoparticles. Furthermore, the optimization of the preparation is carried out chitosomes using ultrasound and magnetic stirrer. Cosmetic products enriched with these nanoparticles were developed and their sensory analysis was proved. This work contributes to the understanding of nanoparticle preparation processes and provides useful information for the development of new cosmetic and food products with improved properties and stability.
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Application of microencapsulation techniques in development of novel controlled-release systems.
Karásková, Iva ; Mravec, Filip (referee) ; Sedláček, Petr (advisor)
This diploma thesis deals with application of microencapsulation techniques in development of hydrogel controlled-release systems in which the main role is played by humic acids, biopolymer chitosan, compound fertilizer NPK and 3-indoleacetic acid. This paper continues my bachelor thesis topic about utilization of polyelectrolyte complexes. The aim of this work was to develop a literature review focusing on the microencapsulation techniques and according to its results optimize the method. Microencapsulation was performed with a commercial encapsulator BUSCHI B-395 Pro and a release of individual components into a water was measured. An amout of released substances was measured by UV-VIS method and HPLC analysis. Practical part also included testing of repeated swelling and drying. It was found that suitable composition and combination of ingredients form hydrogels for further use in agriculture.
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Production of microbial enzymes and their stabilization by encapsulation
Hazuchová, Eva ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The present thesis deals with the production of microbial enzymes and their subsequent stabilization through encapsulation. The theoretical part focuses on microbial enzymes, especially extracellular hydrolases, their producers and characteristics. Within the theory is also discussed the possibility of the application of enzymes in the field of pharmacy and medicine. Experimental work was focused on the actual production of microbial enzymes and methods for their to stabilization. The production of proteolytic and lipolytic enzymes in dependence on time and the used culture substrate were followed. The highest enzyme production was observed in Aspergillus oryzae when cultured on wheat bran at the third day of cultivation. In the experimental part was further carried out the identification, isolation and purification of enzymes. A substantial part of the experiment was to stabilize produced microbial enzymes by encapsulation. Enzymes were entrapped into alginate particles with encapsulation efficiency in the range of 55-70 %. The highest efficiency exhibited encapsulated enzymes from Aspergillus oryzae. Subsequently, long-term stability of the encapsulated enzyme in two environments (in water and gel) was followed during six weeks incomparison with free enzyme. During storage of free enzyme a significant decrease in enzyme activities occured, especially between the fourth and sixth week of storage. On the contrary, in encapsulated increased enzyme activities were observed. Empty particles exhibited higher stability during storage in the gel than in water. In this thesis potential use of enzymes in the pharmaceutical industry as agents promoting digestion was tested too. According to the results, particles with encapsulated microbial enzymes could be considered as suitable for some pharmaceutical applications.
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Addition of probiotics to baby food products
Dudrová, Markéta ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
This Diploma thesis deals with preparation of probiotic cultures Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium breve enriched with prebiotics meant for application in baby food products. Natural extracts from matcha, moringa, young beat, young barley, chlorella and spirulina were selected as prebiotics. The theoretical part is focused on probiotic bacteria, their biological effects and their effects on the child´s body. The experimental part deals with the cultivation of probiotic bacteria with plant extracts, monitoring their viability and stabilization in an encapsulated form. Mixtures of probiotic cells with prebiotics were encapsulated into alginate particles to increase stability. Some of the alginate particles were processed by freeze drying. Mixtures of probiotic cultures with plant extracts were subjected to model human digestion by the action of model digestive juices in unencapsulated, encapsulated and lyophilized form. Selected extracts of plant materials were characterized in terms of amount of total and reducing sugars, total phenolic substances, individual phenolic substances and antioxidant activity. Further, two baby commercial dietary supplements containing probiotics were selected, which were characterized in terms of cell number and viability. Probiotic products were also subjected to model digestion.
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Encapsulation of active components and their applications in food industry
Malčíková, Hana ; Němcová, Andrea (referee) ; Skoumalová, Petra (advisor)
The Diploma thesis is focused on encapsulation of bioactive compounds which are contained in selected superfoods for the purpose of application to childrens nutrition supplements. In view of the nature of selected samples, which are seaweed, walnuts, hemp seed and flax seed, the emphasis is put on the content of omega-3 and omega-6 acids. The theoretical part introduces topic of children food, further it describes the nature of selected superfoods and last but not least it contains screening of available childrens food supplements containing omega-3 fatty acids on the market. In the experimental part, an optimization of the appropriate type of extract was made. A 24 hour aqueous macerate and 20% ethanol macerate were selected for next analyzes. Samples were characterized by content of polyphenols, flavonoids and the antioxidant activity and they were used to forming of extracts were encapsulated into liposomes for which their encapsulation efficiency, stability and long-term stability have been tested. Hexan extracts were also prepared for the same reasons. It was found that liposomes of selected superfoods should not be stored for 12 weeks. The samples were used analyzed for the carbohydrate content by the duboise method, a protein content by the Kjeldahl method and the determination of the fatty acid profile by gas chromatography. Furthermore, the content of carotenoids and chlorophylls in algae samples was determined by spectrophotometry and this analysis was verified by high-performance liquid chromatography. The technique of high-performance liquid chromatography was also used to verified a content of polyphenols in the algae samples. Finally, a sensory analysis of prepared alginate supplements containing algae and cold-pressed oils was performer in combinations to achieve a higher omega-3 and omega-6 fatty acid content. The F01-labeled sample containing wakame algae was evaluated as the best one.
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Characterization and stabilization of pancreatin
Wurstová, Agáta ; Němcová, Andrea (referee) ; Obruča, Stanislav (advisor)
This work focuses on a study of enzyme mixture pancreatin, its characterization and subsequent encapsulation into liposomes. As a reference proteins bovine serum albumin and trypsin were used. Characterization of pancreatin consisted of two parts. The first part focuses on optimization of methods for the concentration determination by absorption spectrophotometry using basic methods for identifying proteins (Biuret method, Hartree-Lowry method and Bradford method). Moreover, UV spectrums of the protein were measured. As a method for identification of protein´s molecular weight, SDS-PAGE was used. To identify components of pancreatin, LPLC was employed in two modifications, ion-exchange chromatography and size exclusion chromatography. The second part is dedicated to the characterization of pancreatin as enzyme in terms of pH and temperature optimum for the enzyme activities of protease (pH 9, 8 and 50 °C), amylase (pH 7 and 40 °C) and lipase (pH 7 and 50 °C). The last part of this work aimed at an encapsulation of pancreatin into liposomes and DLS analysis of distribution of particles and their zeta potential. Liposomes did not spontaneously release encapsulated enzyme. To confirm that proteins were successfully entrapped into liposomes, their structure was disrupted by application of phospholipase D. In conclusion, liposomes can be utilized as delivery systems for native enzymes.
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Development of a new type of energy drinks containing natural active components
Vysoká, Marie ; Němcová, Andrea (referee) ; Skoumalová, Petra (advisor)
The aim of this thesis is the development and preparation of a new energy drink. The theoretical part of the thesis focuses on the comparison of the drinks available in market, the presentation of the main active ingredients and the proposal of enriching the new energy drink. It also describes the possibility of using an encapsulation and the method used to determine specific compound in energy drink or encapsulated particles. In the experimental part of the work, at the beginning, the main content of energy drinks were characterized, for instance caffeine, sugar, polyphenol and vitamin C. Subsequently the energy drink based on selected types of loose teas that were enriched with the encapsulated extract of acai, acerola, maca, goji and ginseng was designed. All extracts contained large amounts of polyphenols and antioxidants. In addition, acerola extracts contained very high amounts of vitamin C. Two types of particles, alginate particles and liposomes were prepared for encapsulation. For all particles, encapsulation efficiency, size, stability, and antioxidant activity were determined. Long-term stability was then monitored within three months. The particles were also exposed to artificial gastric, pancreatic and bile juice. All tested particles showed very good encapsulation efficiency. In terms of long-term storage stability in an aqueous environment. Particularly liposome particles, which also showed high stability by zeta potential measurement, were suitable. On the contrary, in case of alginate particles, when stored in an aqueous medium, the release of active substances occurred. Finally, an energy drink was created and subjected to sensory analysis. The best energy drink was based on black or green tea with alginate particles acai, goji and ginseng.
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Use of some encapsulation techniques to controlled release of active substances in food and cosmetics products.
Skoumalová, Petra ; Rittich, Bohuslav (referee) ; Kráčmar, Stanislav (referee) ; Márová, Ivana (advisor)
The presented doctoral thesis is focused on preparation, characterization and application of organic micro- and nanoparticles as transport systems for active components and some their complex natural sources. Active component were packed into liposomes and polysaccharide particles. As active components were used caffeine, some drugs – clotrimazole and ibuprofen, further antioxidants and vitamins. Antimicrobial herbs and spices extract, antimicrobial peptides lysozyme, nisin and other antimicrobial ingredients were encapsulated too. Encapsulation of selected hydrolytic enzymes was tested, too. Particles were also used for encapsulation of probiotic strains Bifidobacterium breve and Lactobacillus acidophilus and prebiotic components. These prebiotics were co-encapsulated into capsules with probiotic cells. Natural extracts were encapsulated e.g. extracts of guarana, ginseng, goji, green barley, propolis, black, green and white tea, coffee, fruit and vegetable extracts. The efficiency of encapsulation was determined by HPLC/PDA and by spectrophotometry. Long-term stability of particles and amount of released component in model/real foods, in model cosmetic conditions and in a model physiological environment were monitored too. Size of prepared liposomes and polysaccharide particles was determined by dynamic light scattering and by light microscopy and electron microscopy, respectively. Stability of the particles was measured using a zeta potential. Also, analytical centrifugation was used to measurement of sedimentation velocity and stability of the prepared particles. The antimicrobial activity were tested using two Gram-positive (Bacillus subtilis, Micrococcus luteus), two Gram-negative (Escherichia coli, Serratia marcescens) bacteria and one fungal strains (Candida glabrata). For determining the antimicrobial properties of active component and prepared particles two the most widely used methods were used - agar diffusion method and broth dilution method. The viability of probiotic strains were performed using flow cytometry and fluorescence microscopy. Encapsulation of active component was successful in all types of particles. Liposome showed a very good long-term stability mainly in water conditions with neutral pH and polysaccharide particles were stable in acidic conditions. Prepared particles showed a very good stability in model stomach environment, while in model intestines environments particles were disintegrated and active component were released. Prepared particles with encapsulated caffeine as well as other tested antioxidants and vitamins could be used to modern types of energy drinks, food supplements and also for some cosmetics applications. Encapsulated antimicrobial components could be used for food application as well as for cosmetics and pharmaceutical application like antimicrobial wound formulation. Encapsulated enzymes can be used for controlled release of proteases in wound healing, as delivery systems in digestive tract and as a part of pharmaceutical preparative and food supplements for enzyme therapy. The study revealed that encapsulation of probiotics and also co-encapsulation of probiotics with prebiotics exhibited longer stability of particles and survival bacterial cells. So, prepared particles are suitable for use to food product with beneficial effects on the human body.
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Encapsulation of probiotics and prebiotics for use in nutritional products for children
Šnajdarová, Karolína ; Němcová, Andrea (referee) ; Skoumalová, Petra (advisor)
The Diploma thesis deals with designing of probiotic dietary supplement for children with strains Lactobacillus acidophilus and Bifidobacterium breve and with prebiotics. Used prebiotics were Inulin, Chia fiber, Bamboo fiber, Chlorella + Spirulina and Yakon syrup. The theoretical part is focused on probiotics, prebiotics and their biological influence. In experimental part the possibilities of encapsulation into alginate particle and lyophilisation of probiotic cells were observed to find their good form to final nutritional product for children. Several types of probiotic with addition of prebiotics were tested in model conditions of gastrointestinal tract. It was found that addition of prebiotic highly increases viability of probiotic cells and their resistance to model conditions of gastrointestinal tract. In this case, the best prebiotic was found in Yakon syrup. The prebiotics were also characterised in terms of nutritional composition, amount of total and reducing sugars, oligosaccharides, proteins, lipids, polyphenols and chlorophyll were obtained. Finally, Chia fiber, Chlorella + Spirulina and Yakon syrup were chosen as prebiotics with best characterisation/properties. In conclusion, a dietary supplement with lyophilized alginate particles containing probiotic cells and with the most appropriate prebiotics were designed. Forms of the product were powder and gummy-bear.
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