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Selective isolation of of the genus Lactobacillus bacteria from foods
Novotná, Eva ; Šárka, Havlíková (referee) ; Rittich, Bohuslav (advisor)
Probiotic lactic acid bacteria of genus Lactobacillus play an important role in the digestive tract of human. They are used in food processing and they are the part of food supplements. Lactic acid bacteria of the genus Lactobacillus can be identificated by polymerase chain reaction (PCR). Bacterial DNA was isolated from cell lysates of 4 synbiotic food suplements by magnetic particles P(HEMA-co-GMA). Isolated DNA was amplified by genus-specific and species-specific primers. Magnetic particles with immobilized antibodies against Lactobacillus bacteria were used in the next part of thesis. These particles were used for isolation target cells from products with their identification by genus specific PCR.
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Preparation of food supplements for children containing probiotic bacteria and fruit components
Vetchá, Vendula ; Bendová, Agáta (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis is focused on the preparation of supplementary food with probiotic culture and fruit components. The aim of this work was to determine which of the selected extracts will affect the growth of probiotics and also will contain a certain proportion of phenolic compounds, flavonoids, vitamin C and show antioxidant effects. The theoretical part of the work is focused on the intestinal microbiota, the issue of probiotics and the characterization of encapsulation methods of probiotics. We used extracts of teas and fruit syrups in the experimental part. The antimicrobial activity against model microorganisms Escherichia coli, Micrococcus luteus, Staphylococcus epidermidis and Serratia marcescens was analyzed. Interaction of probiotic bacteria Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium breve in extracts were tested. After model digestion, cell viability of probiotic bacteria in combination with extracts was examined during and after digestion. In the last part, encapsulated particles containing probiotics and a mixture of tea and syrup were prepared.
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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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Bioavailability of magnesium and zinc from food supplements
Lindovský, Patrik ; Křikala, Jakub (referee) ; Diviš, Pavel (advisor)
This bachelor's thesis deals with the analysis of dietary supplements containing magnesium and zinc. The analysis examined the content of active substance and solubility in simulated gastric acid. The method used to analyze the active substance content was inductively coupled plasma optical emission spectrometry. This method was also used to determine the degree of solubility of the active substances. A total of thirteen different samples of dietary supplements were examined, all of which contained magnesium as the active ingredient and four of these samples additionally contained zinc. All samples contained the declared amount of magnesium. The zinc amount in food supplements was in accordance with the content stated on the label. In some samples the amount of zinc was determined to be lower, but the deviation from the declared amount did not exceed 14 %. Solubility tests have shown that some products do not contain a suitable type of coating to protect the active substance, which may cause a deterioration in bioavailability.
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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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Mineral and vitamin deficiencies in the elderly and their supplementatin
Nesnidalova, Andrea ; Vágnerová, Tereza (advisor) ; Bárta, Michal (referee)
Seniors often buy inappropriate combinations of dietary supplements based on advertising or peer recommendations, but often to a lesser extent on the recommendation of a professional. It is important for seniors to pay attention to the quality and variety of their diet in order to maintain good health. The bachelor thesis is divided into theoretical and practical parts. In the theoretical part, the first chapter describes the individual vitamins and minerals. The next chapters deal not only with their deficiency and need in the elderly population but also with their correct consumption with regard to further pharmacotherapy. In particular, a chapter dealing with the reasons leading to insufficient food intake in the elderly is described. For the practical part, three main objectives have been set. The research was conducted by questionnaire survey to which a total of 67 respondents aged 65-90 years answered. The first objective was to find out what dietary habits seniors have in their home environment and what vitamins and minerals they are deficient in. A sub-objective of this question was to determine whether current supplementation is justified in this population given the results of the questionnaire survey. The second objective builds on dietary diversity and explores the principles of good...
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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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DEVELOPMENT AND TESTING OF NATURAL FOOD COMPOUNDS FOR INFANTS´ NUTRITION
Hoová, Julie ; Kráčmar, Stanislav (referee) ; Vítová, Eva (referee) ; Márová, Ivana (advisor)
The presented doctoral thesis is focused on development and testing of natural compounds for infant’s nutrition. Selected groups of plant-based food were examined from nutritional point of view, as well as regarding the content of biologically active compounds, especially compounds with antioxidant and antibacterial activity. As basic nutrients were measured following groups of compounds: total saccharides, reducing sugars, insoluble fiber, total nitrogen, and fatty acid profile. Moreover, content of specific vitamins and provitamins, total phenolic compounds, flavonoids, antioxidant capacity, natural pigments, fructans, -glucans and organic acids were determined in selected samples. The evaluation of antimicrobial effect was studied via interaction with appropriate types of microbial cells. The safety of tested materials was verified by cytotoxicity tests using human cell lines HaCaT and Caco-2. In next part of present work, encapsulation techniques were applied to enhance stability and consumer acceptance of natural extracts. Materials were encapsulated into nanoparticles, especially into liposomes of different composition. Size distribution, uniformity, zeta potential, encapsulation efficiency and release control were monitored. Sunflower and soya bean lecithin were determined as the most suitable for preparation of stable liposomes. Further part of the study was focused on the role of probiotics in infant´s nutrition. Selected probiotic strains were cultivated and the influence of the encapsulation techniques and presence of plant extracts on probiotic viability were examined in natural form and in model digestion conditions. Cultivation techniques and flow cytometry were performed to evaluate probiotic viability. Based on the results obtained, plant extracts rich in bioactive compounds and having potential effect on human organism and probiotic bacteria were selected. As a most suitable combination, green barley and some probiotics like lactobacilli and bifidobacteria could be recommended. Finally, the specific study focused on the transfer of selenium species from mother to child via colostrum was analyzed. Selenium is a biogenic element acting as a representative of early natural antioxidants in human body. The important role of colostrum in neonatal nutrition was confirmed by the detection of the presence of selenoprotein P in the colostrum. This protein is further taken up by the child immediately after birth and contributes as the earliest antioxidant to infant´s immunity. Overall, it can be concluded that, despite the undeniable fundamental importance of protein in childhood nutrition, further plant-based biologically active compounds and combinations of probiotics and prebiotics, represent a major benefit and contribute positively to the increase of the nutritional value and quality of foods for infant nutrition.
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