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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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Isolation of active compounds from algae and their application in cosmetic products
Nováková, Laura ; Byrtusová, Dana (referee) ; Skoumalová, Petra (advisor)
The bachelor thesis is dedicated to the study of active substances and antioxidant effects of cultivated microalgae. We compared the results with a commercial alga that is freely available. In the theoretical part we focused on description of algal metabolites in cosmetics and a brief description of the methods used in their testing. In the experimental part there were analyzed three types of extracts (aqueous, alcohol and oil) from 4 species of algae. It is mainly the content of polyphenols, flavonoids and antioxidant activity that is determined. According to the results, the highest content of active substances was found in oil extracts. All extracts were encapsulated into liposomes. The average size of the nanoparticles was in range of 200 nm to 300 nm. The particles were stable enough also for long-term stability. The largest decrease was observed in the oil extract of the cultivated algae Chlorella vulgaris. The cytotoxicity of oil extracts was realized by MTT test on human cell cultures HaCaT. Finally, we concluded that the prepared liposomal particles could be used for anti-aging cosmetics.
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Uses of active compounds from honey in cosmetic products
Balášová, Patricie ; Langová, Denisa (referee) ; Skoumalová, Petra (advisor)
The bachelor thesis was focused on the preparation and characterization of extracts and liposomes with active substances from chosen types of honey with the aim to apply these extracts to the cosmetic products. The extraction of active substances from chosen material was optimized during the work. As the most suitable organic solvent for extraction was chosen diethyl ether. All the extracts were tested on the content of total polyphenols, sugars and antioxidation activity. The final samples were also tested on the content of flavonoids. Extracts were encapsulated to the liposomes, which were tested especially for their antioxidation activity, size and stability. Then, extracts and liposome particles were applied to the cosmetic products. Cosmetic creams and gels were prepared and tested for antioxidation activity and antimicrobial activity against the strains Serattia marcescens and Micrococcus luteus. Antimicrobial activity of gels was proved especially against the strain of grampositive bacterias – Micrococcus luteus. From this point of view another one testing strain was chosen – Propionibacterium acnes. Finally, the chosen liposomes were tested for their contact with human cells, immortalized keratinocytes HaCat. No cytotoxic effect was observed and tested materials can be applied to cosmetics against acne.
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Development and characterization of hydrogel carriers for modern agricultural applications
Mai, Thuy Ha ; Kalina, Michal (referee) ; Sedláček, Petr (advisor)
The bachelor thesis is focused on characterization of hydrogel carriers and their application in agriculture. Entrapment of active phase within the hydrogel matrix would allow release of its content in controlled rate. The theoretical part describes encapsulation techniques and suitable biocompatible materials involved in encapsulation. For the experimental part, the release of soil bacteria Cupriavidus necator H16 from alginate matrix was examined. The focus was on the release rate of bacteria via diffusion and later, on the release rate of bacteria encouraged by chemical or enzymatic reagents. Further modification of carrier was suggested by adding hydrophobic barrier composed of polyhydroxybutyrate (PHB). The modified alginate beads seemed to be more resistant toward enzymatic or chemical agents, thus the process of the release was to some extent suppressed. This fact might suggest PHB as a possible vessel for optimization of controlled release system of hydrogel carriers.
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Encapsulation of soil bacteria in hydrogel carriers
Orišková, Sofia ; Smilek, Jiří (referee) ; Sedláček, Petr (advisor)
The goal of this bachelor thesis was both to review existing literature regarding the topic of inoculation of soil bacteria and test a relevant encapsulation method and optimize it. The evaluation process involved the study of various encapsulation techniques that involve hydrogel carriers suitable for agronomic purposes. Encapsulation allows controlled release of soil bacteria, and protects and stabilizes it, while ensuring longer shelf life. For the practical testing, Cupriavidus necator H16 was chosen as a nitrogen fixing bacteria for the inoculation. Through an ionic gelation method, it was encapsulated into alginate carriers, forming matrix microcapsules. Sodium alginate reacts with the cross-linking agent calcium chloride to form the capsules. The impact on the quality of the product was tested through several variables. What was revealed was that molecular weight of alginate was proven to have a significant impact. Alginate with higher molecular weight was shown to be suitable for the given system. The most desirable environment was distilled water or a TRIS-HCl buffer. However, the TRIS-HCl was unsuitable in cases of retrieving a dry product by lyophilization. Eventually, the viability of encapsulated cells was examined, and it was proven that encapsulated bacteria endure the process of encapsulation in the above-mentioned environment and they were gradually released from the carrier.
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Use of algae extracts in cosmetics
Plášková, Anna ; Rapta, Marek (referee) ; Márová, Ivana (advisor)
This thesis is focused on a preparation of extracts from selected species of algal and cyanobacterial strains, their characterization, a cytotoxicity testing and a use in cosmetic products. The theoretical part contains the review of a taxonomic classification and parameters of algae and cyanobacteria and basic information about used organisms. There is a description of the most significant factors influencing the algae cultivation and production of biomass. Further, active substances of algae and cyanobacteria, which could be used in cosmetic products as UV protective substances, were described. An overview of extraction techniques, encapsulation of active substance into liposomes and particles characterization, antioxidant activity analysis, and cytotoxicity tests is given too. In experimental part, antioxidant activity of algal extracts and chlorophyll a and carotenoid content were determined spectrophotometrically. The long-term stability of extracts was monitored for three weeks. Liposomes were prepared by sonification and encapsulation activity was analysed. The Dynamic Light Scattering method (DLS) was used for analysis of polydispersity and size of liposomes. Colloid stability of particles was determined by zeta potential. Cytotoxicity tests were performed using MTT assay. The prepared extracts, particles and lyophilized biomass of algal and cyanobacterial strain were further used as active substances in the formulation of cosmetic products (type o/w). These creams were tested on human skin.
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Encapsulation of probiotics for use in nutritional products for children
Šmídová, Veronika ; Hudečková, Helena (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis is focused on optimization and development of probiotic food supplement with attractive look and active ingredient, like prebiotic or “superfood”, which are there for afford useful substances for organism. In the theoretical part is focused on probiotics and its encapsulation, also on prebiotics, which are used for work and screening probiotics food supplements in our market. The practical part is focused on optimization of composition of new probiotic food supplement, polysaccharide particles in the shape of a teddy bear were prepared. At first, the basic composition was optimized, as the best alginate-agar particles were determined. Addition of nutritionally valuable ingredients was also optimized. Particles with inulin, acerola, chia fiber, yacon syrup, chlorella and spirulina were prepared. Another part of this work was focused on the determination of the viability of probiotic bacteria Lactobacillus acidophilus and Bifidobacterium breve in various forms and after exposed to model digestion. The highest viability of the cells was measured after encapsulation of lyophilized cells into a polysaccharide particle. Prepared particles were finally subjected to a sensory analysis.
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Interaction of PHA-based particles and fibres with human cells
Tarageľ, Matej ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with the preparation and characterization of PHA based nanoparticles and nanofibers and their subsequent influence on the living human skin cell. Theoretical part is aimed at polyhydroxyalkanoates, preparation of PHA based nanoparticles and nanofibers and methods of their physical, biological and chemical characterization. Further, the theory of liposomes, their clasification, preparation and physical and chemical properties are discussed too. Next, the theoretical part focuses on the cultivation of human cells and general information on selected cell lines. The experimental part is focused on the optimalization of the preparation of liposomes and fibers enriched by PHA. Further, characterization of stability and interactions of these nanomaterials with human HaCaT cells was proved. Cytotoxic and genotoxic tests were performed and determination of concentration of phospholipids in prepared particles was realized too.
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Encapsulation of plant extracts containing phenolic compounds into nanoparticles and nanofibers
Petrželková, Markéta ; Bokrová, Jitka (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis was focused on the encapsulation of extracts containing phenolic substances in order to apply these materials in cosmetics. At work were prepared aqueous, ethanol and lipid extracts of coffee and cocoa. All extracts were characterized on the content of all polyphenols and flavonoids. Their antioxidant aktivity and SPF were also determined. Then the selected extracts were encapsulated into liposomes and polyhydroxybutyrate nanofibres. The basic characteristics of the prepared liposomes were also observed and also their SPF and antioxidant aktivity were monitored. The highest antioxidant aktivity and SPF had liposome particles containing ethanol cocoa extracts. The liposome particles were applied to cosmetic emulsion. These creams evince high antioxidant acitivity and stability determined by analytical centrifugation. Also the prepared nanofibres had high antioxidant aktivity and confirmed the gradual release of the active substances. In conclusion the test cytotoxicity on human keratinocytes confirmed the safety of prepared nanomaterials using the MTT test, which are therefore suitable for cosmetic applications.
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Use and application of natural antimicrobial substances
Dzurická, Lucia ; Byrtusová, Dana (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis is focused on the study of antimicrobial activity of plant substances in combination with bacteriocins and the possibility of creating new encapsulated form of supplement which could be used in food and cosmetic products. 5 plant materials were selected: acerola, cinnamon, cloves, orange peel and yacon syrup. Nisin was chosen as the most suitable bacteriocin. In the theoretical part the components with antimicrobial and antioxidant activity are described, such as the materials of plants and animal origin used in this work. Also the possibility of increasing the antimicrobial effect and possible use of natural antimicrobial substances were described. In experimental part, the aqueous extracts of selected plant materials were firstly spectrophotometrically characterized for the content of total polyphenols, flavonoids and antioxidants. Selected substances were encapsulated into liposomes and subsequently preparation of liposomes coated with chitosan was optimized. The particles were tested for size, short and long term stability, encapsulation efficiency and antioxidant activity. Furthermore, the antimicrobial activities of selected components in nonencapsulated and encapsulated form were observed against four strains of microorganisms (Escherichia coli, Micrococcus luteus, Serratia marcescens and Candida glabrata). Also the expected synergisms of the antimicrobial effects of extracts in combination with nisin and prepared particles were observed.
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