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Potential microbial hazards in actual cosmetology trends - bio, vegan, raw
Jančíková, Simona ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
Bio-, vegan- and raw-cosmetics are continually more popular type of cosmetic products caused by an absence of synthetic and preservative substances but at the same time there is an increased probability of microbial contamination. The main aim of this thesis is a practical findings of potential microbiological contamination using a challenge test and a determination of any active ingredients in the cosmetic preparations. The legislation of cosmetic preparations as well as the information about certificates, which are awarded for bio-, vegan- and raw-cosmetics has been processed in the theory. This section also discusses a composition of vegetable and essential oils, which are used as raw materials in cosmetics production to a great extent and have a positive effect on skin. This thesis also deals with a possible microbiological contamination, listing the most frequently occurred pathogenic microorganisms, which can have a negative influence on consumer health. Operating life of selected samples using the Schülke Koko test by inoculating selected representatives of bacteria, yeasts and molds (Candida glabrata, Escherichia coli, Pseudomonas aeruginosa and Aspergillus niger) are being tested in the practical part. In addition a possible antimicrobial activity which may partially replace an effect of synthetic preservatives in the presence of essential oils is also being tested. Finally any biological active substances were analysed by the gas chromatography, in particular fatty acids contained in the creams.
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Compounds of terpenic nature in mint plants and the influence of elicitation on them
Jančová, Nikola ; Čáslavský, Josef (referee) ; Vávrová, Milada (advisor)
Diploma thesis is focused on study of compounds of terpenic nature in mint plants. Terpenic compounds are volatile hydrocarbons formed by several isoprenoid units with low molecular weight which cause the typical smell of plants. Presence of these compounds cause that plants seem to be fungicidal, bactericidal and insecticidal. Due to these properties, they can be used as botanical pesticides which are not toxic and no resistant organisms occur. Each plant contains relatively low concentrations of these compounds and therefore elicitors must be used for the increasing of terpenes amount. Elicitors activate defensive mechanisms in the plant leading to higher defense abilities and production of secondary metabolites. The identification and quantification of analytes was determined by gas chromatography in connection with mass spectrometry.
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Čerstvost a trvanlivost rybích produktů
HAO, Ruoyi
Fish plays an important role in the human diet and health as a source of easily digestible and highly nutritious animal protein and high value n-3 polyunsaturated fatty acids (n-3 PUFA). However, with high moisture, low amount of connective tissues, and neutral pH value, fish muscle is more perishable than other food muscles. Fish freshness depends on physical, chemical, biochemical, and microbiological changes during the post-mortem, which is crucial to fish quality. Generally, fish muscle deterioration depends on three mechanisms: enzymatic autolysis, lipid or protein oxidation, and microbial growth. The deterioration of fish quality is a complex process affected by the nutrient profile of muscles, microorganisms, storage conditions. Nowadays, a farming culture system of omega-3 carp, enabling the increase of healthy n-3 PUFA in common carp muscle, was developed in the Czech Republic. The benefits of this carp on human health have been proven. However, the knowledge of the potential intervention by the innovative culture system on the nutrients pattern, spoilage process, and freshness of carp is not available yet. Nowadays, chill-stored fish is turning into popular fish food with the encouragement of available cold-chains and promoting healthy consumption concepts of fresh food. Nevertheless, fish quality still deteriorates severely during chilled storage, leading to freshness and shelf-life reduction. The rapid growth and metabolism of microorganisms naturally present or from contamination drive this process. However, recent studies did not comprehensively investigate the microorganisms' role in the freshness reduction of chilled stored fish. Moreover, driven by 'green consumerism', foods with few synthetic additives but more natural ingredients are popular, promoting essential oils (EOs) attracting much attention for fish preservation in recent years. However, the preserving effects of these EOs on fish are inconsistent. Thus, how to establish a good preservation strategy for using EOs-based preservation methods to manipulate microbial spoilage and maintain the freshness of chill-stored fish. This thesis is devoted to filling these knowledge gaps. 1) The patented farming system was found a slight increase in storage stability and shelf-life of carp via the investigation on the differences in the potential nutrients, post-mortem freshness, and shelf life between traditionally cultured common carp and omega-3 carp. 2) The relationships among typical freshness indicators and several dominant spoilage microorganisms and the manipulation of spoilage microorganisms by EOs-based preserving method in chill-stored fish were exposed. 3) A sensory acceptable EOs-based antibacterial coating was developed for the preservation of chill stored fish fillets. 4) Intelligent strategies for maintaining fish gel food freshness and properties via phenolic compounds and ultrasound treatment by enhancing protein cross-linking were established.
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Repelentní účinky silic vybraných rostlinných druhů
Mašláňová, Hana
The summer season is accompanied by an increased incidence of diptera in livestock farming. The insect is a vector of many diseases and in high frequencies reduce milk and meat production. Significant economic losses in cattle breeding are mainly caused by cosmopolitan synanthropic and synbovine species Musca domestica, Stomoxys calcitrans and Haematobia irritatans. An alternative way of controlling insects without negative affecting health and the environment is the application of the herbal preparations containing repellent essential oils. Formulated mixture of essential oils Mentha x piperita, Pelargonium sp. and Nepeta cataria and essential oils Cymbopogon citratus, Cymbopogon nardus and Eucalyptus globulus were able to repel insects for 6 hours with 87% and 73% efficacy on cattle.
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Mechanisms and mode of action of essential oils on fungi
Ježková, Tereza ; Koukol, Ondřej (advisor) ; Čmoková, Adéla (referee)
Essential oils are volatile compounds from plants with a wide range of effects. Many of them exhibit antifungal activity. As the resistance of pathogenic fungi to antimycotics is increasing, finding new antifungal agents for the treatment of fungal infections is highly desirable. In order to use essential oils for the production of new drugs, it is necessary to know the exact mechanism of their action. Although it is known a lot about the effects of essential oils on fungi, the particular target in a cell is not always described. In this thesis I summarize the present knowledge about the mechanisms of actions on fungi. I gradually deal with effects of essential oils on cell wall, plasma membrane, mitochondrion, nucleus, quorum sensing, virulence factors, mycotoxin production and fungal development. Generally essential oils do not act on one structure but affect multiple structures and processes at the same time. In the last chapter I mention possible directions for further research of these substances. Key words: essential oils, fungi, antifungal activity, mechanism of action, mode of action
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Studium účinků směsi esenciálních olejů ve výživě dojnic
Vojkovský, Jiří
The aim of this diploma thesis was evaulating addition of mixture of essential oils into the diet of high yielding cows and its affect on their performance. Cows were divided into 2 groups (P a K), 18 cows in each group. Both groups were fed by the same diet, the only difference was another kind of premin. The diet of group P inclueded mixture of essential oils with dose 1,2 g per cow per day. During the 100 days lasting expe-riment, dry matter intake, milk yield, milk components, rumen fluid and blood composi-tion were monitored. The results were processed and statistically evaluated. The results show conclusive decrease (P < 0,05) of dry matter intake in group P by 0,83 kg.day-1 (3,22 %). The most economic impact is conclusive decrease (P < 0,05) of milk yield in average of 3,72 kg (8,8 %) per cow per day. Simultaneously there was a decrease in milk fat concentration of 12,17 %. On the other hand, the concentration of milk protein was slightly increased in group P.
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Potential microbial hazards in actual cosmetology trends - bio, vegan, raw
Jančíková, Simona ; Skoumalová, Petra (referee) ; Němcová, Andrea (advisor)
Bio-, vegan- and raw-cosmetics are continually more popular type of cosmetic products caused by an absence of synthetic and preservative substances but at the same time there is an increased probability of microbial contamination. The main aim of this thesis is a practical findings of potential microbiological contamination using a challenge test and a determination of any active ingredients in the cosmetic preparations. The legislation of cosmetic preparations as well as the information about certificates, which are awarded for bio-, vegan- and raw-cosmetics has been processed in the theory. This section also discusses a composition of vegetable and essential oils, which are used as raw materials in cosmetics production to a great extent and have a positive effect on skin. This thesis also deals with a possible microbiological contamination, listing the most frequently occurred pathogenic microorganisms, which can have a negative influence on consumer health. Operating life of selected samples using the Schülke Koko test by inoculating selected representatives of bacteria, yeasts and molds (Candida glabrata, Escherichia coli, Pseudomonas aeruginosa and Aspergillus niger) are being tested in the practical part. In addition a possible antimicrobial activity which may partially replace an effect of synthetic preservatives in the presence of essential oils is also being tested. Finally any biological active substances were analysed by the gas chromatography, in particular fatty acids contained in the creams.
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Compounds of terpenic nature in mint plants and the influence of elicitation on them
Jančová, Nikola ; Čáslavský, Josef (referee) ; Vávrová, Milada (advisor)
Diploma thesis is focused on study of compounds of terpenic nature in mint plants. Terpenic compounds are volatile hydrocarbons formed by several isoprenoid units with low molecular weight which cause the typical smell of plants. Presence of these compounds cause that plants seem to be fungicidal, bactericidal and insecticidal. Due to these properties, they can be used as botanical pesticides which are not toxic and no resistant organisms occur. Each plant contains relatively low concentrations of these compounds and therefore elicitors must be used for the increasing of terpenes amount. Elicitors activate defensive mechanisms in the plant leading to higher defense abilities and production of secondary metabolites. The identification and quantification of analytes was determined by gas chromatography in connection with mass spectrometry.
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The influence of essential oils on nematode Heterodera schachtii
Rejchrtová, Pavlína ; Zouhar, Miloslav (advisor) ; Mazáková, Jana (referee)
The sugarbeet cyst nematode (Heterodera schachtii) belong to one of the most importatnt pests of sugar beet in our country and also worldwide. Its occurrence cause economic losses on growing sugar beet. High contamination of fields can lead to interruption of cultivation of sugar beet.
The purpose of my thesis was make searches on topic of the sugarbeet cyst nematode (BCN), its occurrence, life cycle, the symptoms of attack and preventive and other protection options. Next target was examinete the impact of selected essential oils on mortality of H. schachtii and their direct or indirect effects on BCN under controlled greenhouse conditions in pot experiment.
For testing of dirrect effect of essential oils 23 various essential oils from two companies (Salus and Sigma) were taken. Firstly 0,5 % concentration of essential oils was tested. For each variant was established three replicates, and two control variant. The sugarbeet cyst nematodes were exposed to the direct action of the essential oils for 24 hours, then the experiment was evaluated. In the case of essences FV, FEO, ANO, PA and TAO were further tested concentrations of 0,4 %, 0,3 %, 0,2 % and 0,1 %. For testing of indirrect effect of essences were ranked five essential oils (FV, FEO, PA, ANO, TAO) showing in the direct effect testing experiment 100% efficiency on nematode mortality. After 24 hours of incubation, the fitrate papers with nematodes were transfered into Baerman funnels and living nematode were extracted and counted. For testing the efficiency of essential oils under in vivo conditions were established pot tests under controlled greenhouse condition. It was founded 5 variants (FV, FEO, PA, ANO, TAO) and control variant (K), each of the five repetions. After 90 days was experiment evaluated by extraction of nematode cysts by Fenwick can.
From the experimental results I can conclude, that different essential oils used in this study showed various effectiveness on mortality of sugar beet cyst nematode. Results of pot experiment suggest statisticaly significant difference of the number of cysts. Results of pot tests also showed, that essential oils had also some influence on the growth characteristics of sugar beet, namely ground biomass and root system weight.
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