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Disinfectants in food
Romanská, Veronika ; Vítová, Eva (referee) ; Vránová, Dana (advisor)
The aim the of bachelor thesis is description of chemical disinfection, which is used in food industry to eliminate microbial contaminations of food, food intermediates and foodborne diseases, which can occur if hygienic regulations are not observed correctly. The experimental part of the bachelor thesis characterizes the method which was used to specify the disinfecting effect. This method was used to determine two types of disinfectants which contain two different active ingredients. Based on the results, two disinfectants were evaluated and compared.
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Posouzení vlivu země původu a způsobu zpracování na mikrobiotu vybraného koření
Menoušková, Karolína
The diploma thesis deals with the requirements for the quality of spices. It mainly deals with the microbial contamination of spices, factors of influence and possible means to prevent its contamination. Furthermore, the work deals with the characteristics of spices of the genus Capsicum, its range and possible use. In the practical part of the work, the microbial contamination of spices in peppers and chilli was determined. Individual spice samples differed depending on the country of origin, the method of technological processing, physical treatment and the content of capsaicin. During the microbiological analysis, the total number of microorganisms (CPM), the numbers of coliform bacteria and Escherichia coli, moulds and yeast, or the presence of Clostridum perfringens were monitored. The highest CPM value (4,49 log KTJ·g−1) was detected in the sample of ground chilli from China. A higher number of coliform bacteria and E. coli (2,49 log KTJ·g−1) was observed in the sample of sweet pepper from Spain. A significantly higher number of moulds and yeasts (3,13 log KTJ·g−1) was recorded in the sample of ground goulash pepper from the Czech Republic. In the case of Cl. perfringens, the presence of this bacterium was showed in 3 of 13 pepper and chilli spice samples. During the laboratory experiment, no significant deviations of occurrence of the monitored microorganisms were detected in comparison with the recommended limits or the results of scientific studies. The results show that microbial contamination may be affected by the country of origin, the physical treatment, or the alkaloid content of capsaicin, which evidences an antimicrobial activity. When monitoring the effect of technological processing on the spice microbiota, there was no statistically significant difference between the monitored pepper samples (P < 0,05).
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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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Natural enemies of the European spruce bark beetle \kur{Ips typographus}
BÁRTA, Jiří
Bark beetles (Scolitynae) are among the most important pests of forest stands, where they cause extensive damage, especially in spruce monocultures. Their negative effect is to attack the host tree, which is its source of food and at the same time provides them with space for reproduction. The bark beetle is able to have several generations per year under suitable temperature conditions. One of the most widespread is consi-dered to be the European spruce bark beetle Ips typographus. This species is able to search for weakened and abiotically damaged trees. Integrated Pest Management of forests includes several effective methods against bark beetles. The most used met-hods include the installation of feromone traps, traps trees and poisoned tripods. The European spruce bark beetle is in their population regulated by many natural enemies. From parasitoids such as Coeloides bostrichorum and Rhopalicus tutela and predators Thanasimus formicarius and Medetera spp. to pathogenic microorganisms such as entomopathogenic viruses, bacteria, protozoa, microsporidia and especially entomo-pathogenic fungi belonging to the order Hypocreales. The most important species is the fungus Beauveria bassiana, which has the greatest potential in the biological pro-tection of spruce stands.
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Patogénne mikroorganizmy v surovom mlieku
Strnadová, Ivana
This thesis analyses the occurrence of the pathogenic microorganisms in raw milk. The theoretical part of this thesis focuses on the description of the particular microorganisms, their biochemical activity, their source and the transmission. Furthermore, this thesis analyses the diseases related to these particular microorganisms. In addition, this study discusses a legislation of the raw milk distribution and trade with a focus on its benefits and threats for the final consumers. The practical part includes an analysis of the total number of microorganisms, psychrotrophic bacteria, bacteria Salmonella spp., bacteria Listeria monocytogenes, Staphylococcus aureus and Escherichia coli in raw milk. The samples for this study were collected from the milk automats in the South Moravian region and from the farm in the Pardubice region. Samples were collected during the following year periods: autumn/winter, spring/summer. The analysis includes a comparison of the samples with the legislative limits. Furthermore, the samples were compared with each other in according to the particular period of the year. The last stage of the analysis determines the presence of the inhibitory substances in raw milk.
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Významné patogeny v potravinách
Benešová, Jana
The bachelor thesis deals with summary of the most important pathogenic microorganisms in food, description of their characteristic and methods of detection in food. There are the most common bacterial agens of foodborne disease in the European Union in last 5 years. The thesis clearly describes common alimentary infections and alimentary poisoning, the impacts on human health and their present occurence. The final part is devoted to the basic rules to prevent the risk of these diseases. My bachelor thesis helps to raise awareness of this issues.
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Technologicky a hygienicky významné skupiny mikroorganismů osídlující výrobky z kozího mléka
Chybová, Kristýna
The thesis deals with microbiology of dairy products made from goat's milk. The theoretical part deals with goat's milk, dairy products, and last but not least technologically and hygienically relevant microorganisms, located in products made from goat milk. This section also included measures as from unwanted and dangerous microorganisms defend. The practical part includes microbiological determination in 6 goat cheese samples and 5 goat products that were purchased directly on goat farms and in specialized stores. Microbiological analysis identified the following groups of microorganisms: the total number of microorganisms, lactic acid bacteria, yeasts and molds, enterococci and coliforms. The results were evaluated and compared with current legislation
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Mikrobiologická kvalita čerstvých bylin dovážených ze třetích zemí
Bergová, Lucie
This thesis focuses on microbiological quality of fresh herbs from third countries. Analysis of the fresh herbs was performed in a laboratory. Herbal samples was also compared with samples from the Czech Republic and from private production. Some of the herbal packs (consisting of mint, basil and rosemary) were purchased on a public market while others were collected from private productions. Microbiological quality of fresh herbs is very important because the consumers uses them without any proper heat treatment. The laboratory experiment determined the content of the molds and the yeasts, the total number of microorganisms, the coliform microorganisms and the Escherichia coli. All presented samples were also tested to check any presence of Salmonella spp. There were tested 24 samples of the different herbs of different origin. The method of conducting such experiment was plate-based. The results show that does not matter the origin of the herb, but it depends on the type of herb. It was found that the limits for the determination of bacteria Escherichia coli were exceeded. The presence of Salmonella spp. in 25 grams of herb was detected.
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Laboratory evaluation of activity of traditional Ecuadorian medicinal plants
Klepáčková, Kateřina ; Klouček, Pavel (advisor) ; Přemysl, Přemysl (referee)
Health care in Ecuador varies greatly depending on socioeconomic status, age, sex and place of residence. One third of the population has no regular access to health services and more than two-thirds of the population has no health insurance. Herbal medicine is
the synthesis of therapeutic experience of indigenous physicians which has been evolving
for hundreds of years and its resources are used to prevent and treat various types of diseases. Plants are popular natural remedy due to their efficacy, safety and minimal side effects. However, certain combinations of herbal medicine and drugs can be dangerous. Sciences, which help to examine the context of the traditional use of plants in the timeframe and also contribute to the discovery of their bioactive compounds, are called ethnobotany and ethnopharmacology. This paper investigates ten plants imported from Ecuador, which are traditionally used for healing various types of diseases such as gastrointestinal disorders, influenza, cold, urinary tract infection, skin diseases in the pelvic cavity etc. Efficiency research of herbal medicine has a great significance for future healthcare because
of the expansion of antimicrobial resistance, which is currently becoming a serious health risk for both humans and animals. Antimicrobial and antioxidant activity of plants, which are
in this thesis measured by the broth microdilution method and ORAC method, are important indicators for the analysis of medicinal plants. The only demonstrable positive result
of testing the antimicrobial activity was the discovery of minimum inhibitory concentration
of Espeletia schultzii against Streptococcus pyogenes (MIC=0.256 mg/mL). The highest antioxidant activity was discovered in the plant Croton elegans Kunth (743,64 +- 28,56 microgram of trolox equal to 1 miligram of the extract), for which no records associated to antioxidant activity were found.
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