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Evaluation of the influence of the pasterization and filtration on selected chemical components of beer
Vopelková, Dominika ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
The aim of this work was to study the influence of the pasteurization and filtration on selected chemical compounds in beer. Specifically, the influence on elemental composition, content of organic acids, carbohydrates and phenolic substances was studied. Optical emission spectrometry with inductively coupled plasma (ICP-OES) was used for elemental analysis of beer. Analysis of organic acids was evaluated by Ion chromatography. For analysis of carbohydrates was used High performance liquid chromatography with ELSD detector (HPLC-ELSD), phenolic compounds was evaluated by HPLC with diode array detector (HPLC-DAD). Data from analysis of beer was performed by usage of statistical methods (analysis of variance and principal component analysis). Parameters that showed the most significant differences between individual groups of beers were obtained. Correlations between the variables and the technological beer processing operations were found. 12 parameters of total 23 were affected. The effect of filtration and pasteurization was observed in content of the iron, silicon, potassium and magnesium, malate, monosaccharides glucose and fructose and phenolic compounds.
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In vitro study of antioxidant activity of food supplements
Vopelková, Dominika ; Pořízka, Jaromír (referee) ; Omelka, Ladislav (advisor)
Bachelor thesis deals with the determination of antioxidant activity of food supplements in vitro. The theoretical part focuses on legislative requirements of food supplements, their characteristic and classification. Further, the attention is also devoted to antioxidants, their properties, effects, importance and utilization. Separate chapter describes herbs, which are an essential component of researched supplements, their effects and properties. For experimental part several food supplements in various forms (capsule, tea, juice, dried fruits) were chosen and total content of polyphenols was determined using the UV-VIS spectroscopy. Further, the total antioxidant activity is characterized by electron paramagnetic resonance involving DPPH method.
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Evaluation of the influence of the pasterization and filtration on selected chemical components of beer
Vopelková, Dominika ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
The aim of this work was to study the influence of the pasteurization and filtration on selected chemical compounds in beer. Specifically, the influence on elemental composition, content of organic acids, carbohydrates and phenolic substances was studied. Optical emission spectrometry with inductively coupled plasma (ICP-OES) was used for elemental analysis of beer. Analysis of organic acids was evaluated by Ion chromatography. For analysis of carbohydrates was used High performance liquid chromatography with ELSD detector (HPLC-ELSD), phenolic compounds was evaluated by HPLC with diode array detector (HPLC-DAD). Data from analysis of beer was performed by usage of statistical methods (analysis of variance and principal component analysis). Parameters that showed the most significant differences between individual groups of beers were obtained. Correlations between the variables and the technological beer processing operations were found. 12 parameters of total 23 were affected. The effect of filtration and pasteurization was observed in content of the iron, silicon, potassium and magnesium, malate, monosaccharides glucose and fructose and phenolic compounds.
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In vitro study of antioxidant activity of food supplements
Vopelková, Dominika ; Pořízka, Jaromír (referee) ; Omelka, Ladislav (advisor)
Bachelor thesis deals with the determination of antioxidant activity of food supplements in vitro. The theoretical part focuses on legislative requirements of food supplements, their characteristic and classification. Further, the attention is also devoted to antioxidants, their properties, effects, importance and utilization. Separate chapter describes herbs, which are an essential component of researched supplements, their effects and properties. For experimental part several food supplements in various forms (capsule, tea, juice, dried fruits) were chosen and total content of polyphenols was determined using the UV-VIS spectroscopy. Further, the total antioxidant activity is characterized by electron paramagnetic resonance involving DPPH method.
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