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Effect of antimicrobial substances on "raw food" durability
Horká, Daniela ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
Submitted diploma thesis deals with an effect of antimicrobial substances on raw food durability. Nowadays, the raw food has become very required style of nutrition, which is being practised by more and more people. The issue is that this kind of alimentation, especially vegetable raw food is not prepared in heat treatment which is higher than 42–45 °C. The main aim of the thesis is to study antioxidant and antibacterial properties of the herbal and spice extracts and their following implementation into raw desserts to prolong their durability. At the beginning of the theoretical part, there is an analysis of the issue of raw food and the description of micro-organisms, which are mostly occurred on plant materials. Afterwards, selected herbs and spices, and mechanisms of their antimicrobial effects, and also the methods used to test the products are characterised. The experimental part focuses on characterization of ethanol extracts from 13 selected kinds of spices and herbs. The determination of biologically active substance was accomplished, specifically, polyphenols, flavonoids, anthocyanins and their antioxidant properties. Moreover, these extracts were tested to antimicrobial effect towards gram-positive species of germs Micrococcus luteus, gram-negative species of germs Escherichia coli and yeast Candida glabrata. The molecular part of the thesis contains the DNA isolation from the tested raw material, which was enriched of combination of the selected herbs and spices. Change of expiry date of selected samples of raw desserts was monitored. The presence of chosen micro-organisms was confirmed by the PCR method.
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Microbial contamination of raw food and cereal products
VENGLOVIČOVÁ, Kristýna
Plasma has been increasingly used in recent years due to its lethal effect on microorganisms. Foods treated in this way are not a risk to humans in terms of chemical substance. The literature search is focused on raw foods. Description of pathogenic microorganisms frequently occurring on seeds and methods of disposal feasible in accordance with the rules of the raw diet. The aim of this bachelor thesis was to evaluate the effect of low-temperature plasma on seeds. Seed groups were exposed to plasma for 4, 5, 6, 7 and 8 minutes. Seeds of mung beans, broccoli, watercress, radish and barley were treated with the plasma generated in the vacuum chamber. First of all was evaluated the inhibitory effect of plasma treatment on microorganisms occurring on seeds. Furthermore was monitored the impact on the growth of sprouts and roots. Could not be demonstrated the inhibitory effect of plasma on microorganisms present on seeds. The treated seeds compared to the untreated control group were contaminated with a similar amount of microorganisms. The effect on seed development was different for each species.
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Relationship of students of the selected secondary schools to the alternative ways of eating
Fialová Krejzová, Lenka ; Váchová, Alena (advisor) ; Kovaříková, Miroslava (referee)
The diploma thesis deals with the relationships and opinions of students of selected secondary schools, which are connected with alternative ways of eating. The theoretical part contains basic information about rational nutrition, individual nutrients, there is a comparison of the food pyramid and a healthy plate. Last but not least, alternative diets are also clarified and then information on five specific types of alternative diets is given. In the individual subchapters, vegetarianism, veganism, raw food, paleo diet and a gluten-free diet are mentioned. The aim of the practical part is to find out the opinion of students of selected secondary schools on alternative ways of eating. These are my chosen secondary schools in the Rakovnicko region. A questionnaire survey is used as a research tool. Based on the data obtained, the questionnaire was evaluated and the results were converted into tables and graphs, which are always commented. 187 respondents answered the questionnaire. It was found that 19 of all respondents have nutrition-related health restrictions. The surprising result is that students did not learn about alternative meals primarily at school, but from their own resources (friends, family, etc.). The results of the questionnaire survey point to the fact that secondary school students...
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Effect of antimicrobial substances on "raw food" durability
Horká, Daniela ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
Submitted diploma thesis deals with an effect of antimicrobial substances on raw food durability. Nowadays, the raw food has become very required style of nutrition, which is being practised by more and more people. The issue is that this kind of alimentation, especially vegetable raw food is not prepared in heat treatment which is higher than 42–45 °C. The main aim of the thesis is to study antioxidant and antibacterial properties of the herbal and spice extracts and their following implementation into raw desserts to prolong their durability. At the beginning of the theoretical part, there is an analysis of the issue of raw food and the description of micro-organisms, which are mostly occurred on plant materials. Afterwards, selected herbs and spices, and mechanisms of their antimicrobial effects, and also the methods used to test the products are characterised. The experimental part focuses on characterization of ethanol extracts from 13 selected kinds of spices and herbs. The determination of biologically active substance was accomplished, specifically, polyphenols, flavonoids, anthocyanins and their antioxidant properties. Moreover, these extracts were tested to antimicrobial effect towards gram-positive species of germs Micrococcus luteus, gram-negative species of germs Escherichia coli and yeast Candida glabrata. The molecular part of the thesis contains the DNA isolation from the tested raw material, which was enriched of combination of the selected herbs and spices. Change of expiry date of selected samples of raw desserts was monitored. The presence of chosen micro-organisms was confirmed by the PCR method.
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