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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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Encapsulation of lactic acid bacteria
Vrtná, Monika ; Lichnová, Andrea (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on encapsulation of two strains of probiotic bacteria. Lactic acid bacteria were encapsulated into several types of materials, mostly polysaccharides. The theoretical part describes the techniques of encapsulation applicable in the food industry. During the experimental part alginate and chitosan microparticles were prepared. These particles exhibited different sizes and some of them were modified by starch and carboxymethyl cellulose. Particles were used for encapsulation of two strains - Bifidobacterium breve and Lactobacillus acidophilus. Using flow cytometry cell viability was measured after 24-hours cultivation of bacteria. Particles were observed immediately after encapsulation by optical microscopy and then long-term stability in model foods was evaluated after two days, a week and after four weeks of incubation. Using the Bürker chamber the alived and death bacteria were counted inside and outside the capsule. The stability and viability of the cells were studied also in the artificial intestinal, stomach and bile juices. As the best material for encapsulation of lactic acid bacteria 2% alginate modified by carboxymethyl cellulose was found. The highest viability of bacteria was observed in milk as the real model food. Prepared particles are suitable for use in the food industry.
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Plant-based cosmetic products
Horváthová, Iveta ; Pavelková, Renata (referee) ; Skoumalová, Petra (advisor)
The aim of this bachelor thesis was studying an antimicrobial activity of selected herbal extracts and their encapsulated forms as liposomes. Furthemore, the thesis focuses on determonation of biologically active compounds, natural pigments and antioxidant activity. 6 kinds of herbs were studied - Humulus lupulus, Matricaria chamomilla, Taraxum officinale, Bellis Perennis, Cymbopogon citratus and Rubus Fruticosus. In teoretical part, the general characteristics of herbs and their use are described, it also includes the description of active compounds, microorganisms and used methods. Practical part is focused on characterisation of herbs from the perspective of antioxidant activity, determination of totaly phenolic content and flavonoids, chlorophyll and carotenoids. For analysis of antioxidant activity, concentration of phenolic compounds and flavonoids and antimicrobial activity aqueous and 20% ethanol extracts were prepared. Based on the obtained results, selected extracts were encapsulated into various types of liposomes consisting egg yolk, soy or sunflower lecithin. Generally, ethanol extracts showed higher content of active compounds. For chlorophyll and total carotenoid content determination the highest content of natural pigments was found in Taraxum officinale. Furthemore, antimicrobial activity of extracts and liposomes against 6 strains were determined - Micrococcus luteus, Serratia marcescens, Escherichia coli, Propionibacterium acnes, Staphylococcus epidermidis and Candida glabrata. The highest inhibitory effect was found in Matricaria chamomilla and Cymbopogon citratus samples. Encapsulation effectivity, size, stability and long-term stability of liposomes after a week and two months were determined. From the perspective of zeta potential all the particles were stable and reached a good encapsulation effectivity. It turned out that after two monts of storage the particles decomposed and active compounds into surroundings were released. Selected herbs generally had high content of antioxidants and active compouds. The most suitable lecithin for encapsulation was shown to be sunflower lecithin.
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Encapsulation of caffeine
Patočková, Klára ; Pekař, Miloslav (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on possibilities of encapsulation caffeine in micro- and nanoparticles. In the theoretical part was devoted to information about caffeine, liposomes and polysaccharides and also on the techniques of encapsulation. In the experimental part 5 different methods were used for preparation of micro- and nanoparticles with encapsulated caffeine. Caffeine was packaged into liposomes and polysaccharide particles (chitosan/alginate). Encapsulation’s effectiveness was determined by HPLC/UV-VIS. Prepared particles were monitored for size and stability by dynamic light scattering. The particles were exposed to the arteficial stomach and intestinal juices and bile acids. Particle stability and amount of released caffeine was monitored. Analytical centrifugation was used to measurement of sedimentation velocity and stability of the prepared particles. Caffeine containing particles were added in several soft drinks to determine particles amount when turbidity occurred.
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Isolation, characterization and application of active components of prickly pear and aloe vera
Kocúrová, Petra ; Vysoká, Marie (referee) ; Skoumalová, Petra (advisor)
The main goal of this bachelor thesis was the study of antioxidant and antibacterial effect of natural plant extracts, specifically from pulp and peel of leaf of Aloe vera and Opuntia ficus–indica. Liposomes with encapsulated active compounds were prepared and their use in food and cosmetics industry was analyzed. The theoretical part was focused on botanical with and phytochemical description of natural plant and their use in nutrition and medical practice. Also encapsulation and methods used to analyze encapsulated substances were described. In the experimental part basic characteristics of extracts from two kinds of plantusing ethanol as a solvent in its different concentration (0 %, 20 %, 40 %, 80 %) were analyzed. Mainly totalcontent of phenolics, flavonoids and total antioxidant activity were determined. Selected extracts were also encapsulated into liposomes and the encapsulation efficienty, size, stability and long–term stability of liposomes were determined. Antibacterial activity was tested against Grampositive Micrococcus luteus, Staphylococcus epidermidis and Propionibacterium acnes and Gramnegative Serratia marcescems a Escherichia coli. Moreover, antibacterial acvivity against yeast Candida glabrata was tested. Finally, 2 ethanol extracts of plant samples were tested in terms of cytotoxicity by using cell line Caco–2 and profile of selected phenolic compounds ere determined in the selected extract samples by using high performance liqiud chromatography. 20% ethanol solution was chosen as the most efficient extract solvent which contained the highest concentration of total phenolic content and concurrently all tested extracts showed antioxidant activity. However, there was minimal or none antibacterial effect. Prepared liposomes from extracts were stable. Also product for cosmetics and food industry was designed, specifically healing gel with moisturizing effect and paste made of liposomes as food supplement for athletes.
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Perspektivy využití laktoferinu
Pavlík, Patrik
The thesis is focused on summarization of knowledge on lactoferrin, its sources of production, methods of isolation, biochemical properties, structure and resistance to denaturation under different conditions. At the same time, the biological effects of lactoferrin on the human body are specified, mainly focusing on antiviral effects, immune support and athletes performance enhancement. Moreover, the encapsulation methods of Lf and its delivery to the body are described here, where the most effective method of Lf, still remains the oral administration method. The current utilization of Lf in food processing and other fields is discussed. In the experimental part, food matrices suitable for 3D printable edible coating were prepared. By following encapsulation of Lf into food matrix, a functional food can be developed.
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Ovlivnění životaschopnosti enkapsulovaných bakterií přídavkem vybraných druhů nutrientů
Resová, Daniela
Probiotics are sensitive to external conditions, which can result in reduced viability during handling, processing and storage. One option to increase viability and stability is to immobilize them. In the experimental part of this thesis, probiotic bacteria, specifically a collection strain of Lb. rhamnosus, are lyophilized with the addition of cryoprotectants. The culture enriched with 10% sucrose solution or 2.5% glycerol solution was lyophilized and then the suitability of the substances for the protection of the lyophilized bacteria was evaluated. Sucrose was chosen as the more suitable cryoprotectant since the decrease in viability after lyophilization was only 3.28% of the original amount of CTCs before lyophilization. The decrease in the control and glycerol sample was statistically significant (p < 0.01). Encapsulation of Lb. rhamnosus by extrusion method was also introduced in this study. Nutrients were added to the alginate matrix and then the effect of encapsulation, added nutrients and capsule dissolution on the viability of the encapsulated probiotics was tested. The nutrient with the most favourable effect on the viability and stability of Lb. rhamnosus was evaluated to be alginate with the addition of whey. Compared to the alginate variant with the addition of inulin and the control, a statistically significant difference was observed (p < 0.01). The same viability test was performed after 2 weeks of storage at 4 °C. Storage had a negative effect on all the variants. However, the smallest decrease was observed in the control sample and the sample with cryoprotective sucrose and whey addition.
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Možnosti lyofilizace a enkapsulace probiotických kultur
Faitová, Barbora
This bachelor thesis entitled "Options for lyophilization and encapsulation of probiotic cultures" is prepared as a literature search. As such, microorganisms play an important role in human health, hence the effort to spread probiotic bacteria among con-sumers and through food. Because of the limited viability of these cells, treatment by lyophilization or encapsulation is possible. These methods appear to be very suitable as they ensure their stability during storage, incorporation into food and passage through the digestive tract where they are exposed to adverse conditions.
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Biodostupnost vitamínu C z různých zdrojů
Gabrhelová, Lucie
Vitamin C is classified as a hydrophilic vitamin and performs several functions in the human body. It is necessary to obtain it from food, because people have lost the ability to create it due to evolution. Fruits and vegetables are the most important food sources. It is a relatively unstable vitamin and its losses can occur during food processing. Therefore, there are gentler methods of adjustment by which it is possible to limit the given losses. In order to increase stability and thus bioavailability, other methods are also used, most often different types of encapsulation. In addition to food, vitamin C can also be obtained from dietary supplements. These are available on the market in several forms, which differ not only in price or appearance, but above all in the bioavailability of vitamin C itself. The most effective form is liposomal vitamin C, which is in this form able to ensure high bioavailability of vitamin C.
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Preparation and characterisation of encapsulated biogenic nanoparticles for medical application
Poláková, Veronika ; Vojtová, Lucy (referee) ; Brtníková, Jana (advisor)
Cieľom tejto bakalárskej práce je príprava a polymérová enkapsulácia antibakteriálnych biogénnych nanočastíc, tak aby sa zvýšila stabilita, znížila cytotoxicita a bola zachovaná ich antibakteriálna aktivita. Teoretická časť obsahuje informácie o regeneratívnej medicíne, bežne používaných nanoštruktúrach v regeneratívnej medicíne, ich vlastnostiach a metódach enkapsulácie. Experimentálna časť popisuje procesy prípravy selénových nanočastíc za použitia rôznych metód so špecifickými stabilizátormi a pokračuje enkapsuláciou do prírodného polyméru. Použité metódy enkapsulácie sú založené na samostatnej polymerizácii a pokrývaní vybraným, v prírode sa vyskytujúcim polymérom s adhezívnymi vlastnosťami. Boli skúmané chemické a fyzikálne vlastnosti čistých a enkapsulovaných selénových nanočastíc, ako je ich koncentrácia a morfológia (veľkosť a tvar), boli skúmané pomocou infračervenej spektrofotometrie s Fourierovou transformáciou a skenovacej transmisnej elektrónovej mikroskopie. Bolo zistené, že rôzne metódy poskytnú nanočastice s rôznou veľkosťou, tvarom a stabilitou. Hlavným výsledkom je vytvorenie a popísanie optimalizovanej metódy syntézy selénových častíc, ich stabilizácia a enkapsulácia. Nanočastice syntetizované touto metódou majú sférický tvar a ich veľkosť sa pohybuje v rozmedzí od 10.5 do 101 nm. Veľkosť väčšiny takto syntetizovaných nanočastíc leží v intervale od 10.5 do 40 nm. Enkapsulované nanočastice sú väčšie a pohybujú sa v hodnotách od 74.5 do 571.5 nm.
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