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Antioxidant activity of green tea extracts
Šedý, Michal ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
This bachelor thesis focuses on antioxidant and biological active compounds present in green tea extracts. Green tea is a rich source of antioxidants and it has been considered a medicinal beverage in the past. Series of compounds contained in green tea extracts exhibits strong antioxidant effects. The theoretical part of this thesis deals with the history and production process of tea. It also focuses on the description of the most abundant antioxidant and bioactive substances in tea. Three green tea samples from the retail chain were selected in the experimental section, which were further analysed by selected UV-VIS spectrometry methods and then compared.
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Determination of selected metals in tea samples and bag materials
Hlávka, Jan ; Nováková, Eliška (advisor) ; Hraníček, Jakub (referee)
This bachelor thesis is dealing with determination of antimony in materials modern pyramid-shape tea bags. Possible presence of antimony in these materials, e.g. polyethylene terephthalate (PET) or mixed materials, is caused by using it like catalyst in production of polyethylene terphthalete. The goal of this bachelor thesis is the verification of hypothesis, that antimony is present in materials of pyramide tea bags and that it is released to consumed drink, if higher concentration of antimony is present, and that it could pose a health risk to the consumer. At the same time, I studied if tea leaves are contaminated by other toxic elements, from which some can result from intesive agricultural production. They can be used as pesticides or be presnet in industrial fertilizers. In this thesis I examined the content of As, Cd, Cu, Sb and Zn in tea leaves sold in pyramide bags. These pyramide bags were purchased in local supermarkets and shops. The content of Sb in bags was determined too. The applied method included the decomposition of samples in a microwave decomposition device and analysis of the composition of the resulting solution by the ICP-MS method. Determined contents of the investigated elements were expressed like content of element in the sample in dry mass and the results were compared...
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Antioxidant activity of green tea extracts
Šedý, Michal ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
This bachelor thesis focuses on antioxidant and biological active compounds present in green tea extracts. Green tea is a rich source of antioxidants and it has been considered a medicinal beverage in the past. Series of compounds contained in green tea extracts exhibits strong antioxidant effects. The theoretical part of this thesis deals with the history and production process of tea. It also focuses on the description of the most abundant antioxidant and bioactive substances in tea. Three green tea samples from the retail chain were selected in the experimental section, which were further analysed by selected UV-VIS spectrometry methods and then compared.
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Basic product and sales formats of tea. Tearooms
PACLÍK, Ladislav
This bachelor thesis is oriented primarily on tea and the popularity among its consumers, and also on popularity of the "phenomenon" tearooms in the Czech Republic. The theoretical part of thesis deals with Camellia sinensis, the plant of which is tea produced. The attention is paid to the cultivation of tea as well as on the treatment of tea, the distribution of tea and the trade with tea. Finally, it is also mentioned the distribution of tea according to Czech legislative requirements. The practical part is divided into three parts. The first one is analysis of products and sales formats of tea on Czech market, it means in which forms and where can consumers tea buy (for example in retail network, in pharmacy, in health food store etc.). The second part presents a questionnaire survey, which focuses on consumer preferences in tea consumption and their popularity of tearooms, in order to find out which retail formats of tea are the most popular among the consumers. The third part is based on interview with Mr. Aleš Juřina, the CEO of company Spolek milců čaje, s.r.o., which operates franchise network of tearooms in the Czech Republic, in Slovakia, in Hungary and in the USA.
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