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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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Recipe of a food supplement based on bioactive substances isolated from Prunus spinosa
Červinková, Zuzana ; Hudečková, Helena (referee) ; Kovalčík, Adriána (advisor)
Blackthorn fruits (Prunus spinosa) are small blue-purple drupes containing a range of bioactive substances that give them diverse biological effects. They are traditionally used not only in folk medicine, as they are attributed with many preventive and therapeutic effects. The presented master´s thesis deals with the preparation and characterization of an ethanol extract and dietary supplements based on bioactive substances isolated from the fruits of blackthorn. The ethanol extract was prepared by maceration fresh Prunus spinosa fruits in 40% alcohol. The extract was analyzed for the polyphenols (2111.39±11.32 mg GAE/l), flavonoids (903.89±5.08 mg CAE/l) and anthocyanins (165.24±0.38 mg CGE/l) content, antioxidant (11.99±0.40 mmol TE/l) and antimicrobial activity, phenolic compounds profile and sugars profile. The ethanolic extract exhibited antibacterial effect against the gram-positive bacterium Micrococcus luteus and gram-negative bacterium Escherichia coli but was not effective against the yeast Candida glabrata. After gentle concentration on a vacuum evaporator, the extract was used to prepare a dietary supplement. Two types of dietary supplements were prepared, namely gelatine candies with blackthorn fruit extract and gelatine capsules filled with lyophilized fruit powder. The nutritional profile of these products, content of bioactive substances (i.e. total polyphenols, flavonoids, and anthocyanins), phenolic compound profile and antioxidant activity were characterized. Additionally, the release of polyphenols was monitored during a simulated in vitro digestion. The gelatine candies with different extract concentrations (5, 10, 15 and 20 %) were subjected to sensory evaluation, where the aim was to optimize the addition of the extract to the gelatine matrix. According to the preferences of the evaluators, the sample with 15 % extract was rated as the best in terms of overall taste. In the ranking test, this sample was ranked second, behind the sample with 5 % extract, which, on the other hand, received a worse sensory profile rating. The thesis also included monitoring the effect of freezing, lyophilization, and drying on the bioactive compounds content (i.e. total polyphenols, flavonoids, anthocyanins) and antioxidant activity of Prunus spinosa fruits. The highest contents of total polyphenols (57.49±0.33 mg GAE/g DW), flavonoids (45.75±0.12 mg CAE/g DW) and anthocyanins (6.41±0.19 mg CGE/g DW) were quantified in lyophilized fruits, but the highest antioxidant activity (281.72±0.70 mol TE/g DW) was observed in frozen fruits. A statistically significant moderately strong positive correlation (0.641) of antioxidant activity and total flavonoids was observed for the analyzed samples. The results of the thesis showed a great potential for the use of blackthorn berries in the nutraceutical industry, where they can contribute as active additives to increasing both the bioactive and nutritional quality of dietary supplements.
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Antioxidative parameters of fruit model product.
KRATOCHVÍLOVÁ, Lenka
The content of the main components (anthocyanins, quercetin, chlorogenic acid, L-ascorbic acid, rutin, total polyphenols) was determined in the syrup of elderberries (Sambucus nigra L.) by spectrophotometry or high-performanceliquid chromatography. Furthermore, the antioxidant activity of this syrup was determined using three methods: ABTS, FRAP, and DPPH. The measurement results were statistically processed and compared using correlation analysis, specifically using the Pearson correlation coefficient. It was found that the prepared product contains 2160 mg/kg anthocyanins, 201 mg/kg rutin, 26 mg/kg chlorogenic acid and 679 mg/l polyphenols. No free quercetin was found. The content of L-ascorbic acid in the original elderberries was relatively low and therefore for study purposes, the syrup was enriched with this substance in the amount of 0.5% (w/w) to study the connection of its content with other substances. It is clear from the statistical processing that the concentration of chlorogenic acid correlates with the antioxidant activity measured by the FRAP method and the concentration of polyphenols to the antioxidant activity measured by the DPPH method.
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Preparation of rolls with addition of alternative flours
UHLÍŘOVÁ, Lenka
This bachelor thesis is focused on the production of ordinary pastry with the use of alternative flour. Four kinds of crop flour, made from seed pomace of flax (Linum usitatissimum L.), hemp (Cannabis sativa L.), squash (Cucurbita pepo L.) and milk thistle (Silybum marianum L.), were selected. In the literary part of the thesis, common pastry according to legislation, basic and auxiliary raw materials for production and production technology are all de-fined. The crops, from which the addition to wheat flour was processed, are also described. The practical part deals with the production of five types of wheat buns. Four of them are enriched with 5 % of flour made from seed pomace of the four mentioned crops. Production of buns was followed by sensory evaluation according to the descriptors. Weight lost by baking, the quantity of polyphenolic substances and antioxidant activity were also evaluated.
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Evaluation of beetroot qualitative parameters
MIKEŠOVÁ, Mariana
The thesis si lead to evaluate volume of betalain pigments and analyze antio-xidant activity in selected species of beetroot. The thesis is sorted to several chapters . The first chapter discusses about history, individual species of beetroot and general properties. There are information about antioxidant activity and pigments, which is occure in beetroot in the next. The second part of the thesis is focused on analyze the betalain pigments and evaluate antioxidant activity. It leads to resume, that beetroots with red-violet color are more rich about antioxidant substances. Examination of the individual colours for the selected varieties revealed that the 'Redshine' varieties were mainly rich in beta-cyans and betaxantines. "Monorubra." The highest content of these dyes are the varieties which have the colour of the pulp red to dofia-lova. Their values were significantly higher than those of the 'Boldor F1' variety, which would have been expected to have a higher betaxantine content than the red-coloured varieties
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Production of enzyme hydrolysates from flaxseed proteins and evaluation of their properties
HAŠKOVÁ, Kateřina
This thesis focuses on effect on antioxidant properties and chosen functional properties: solubility, water and fat holding capacity, emulsification activity and stability caused by hydrolysis of protein isolates (PI) made from three different flax varieties (Libra, Agriol and Raciol). Part of this work was production of PI from flax seed. For hydrolysis trypsin, alcalase and papain were used - hydrolysis by trypsin was the mildest, while hydrolysis by papain was the most intensive one. Dynamics and degree of hydrolysis were also observed. Solubility of PI and hydrolysates was discovered to be very high (almost 100%). On the contrary water holding capacity was lower (3,93 g/g and less) than fat holding capacity (4,34 g/g), which increased upon hydrolysis for most enzymes, while water holding capacity decreased. Emulsification activity rised (1,47×) under the effect of hydrolysis, however stability dropped (1,3×). The best emulsifiction properties were found out in trypsin hydrolysates. Hydrolysis caused great impact on content of polyphenols which were in alcalase hydrolysates up to 3× higher and on antioxidant activity which grew in papain hydrolysates up to 2,5×.
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Evaluation of cultivar effect on content of betalain pigments in beetroot
AUEROVÁ, Anežka
The thesis si lead to evaluate volume of betalain dyes and analyze antioxidant activity in selected species of beetroot. The thesis is sorted to several chapters . The first chapter discusses about history, individual species of beetroot and general properties. There are information about antioxidant activity and dyes, which is occure in beetroot in the next. The second part of the thesis is focused on analyze the betalain dyes and evaluate antioxidant activity. It leads to resume, that beetroots with red-violet color are more rich about antioxidant substances. It is more healthier than others.
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