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Influence of coffee making process on chemical composition of brewed coffee
Trenzová, Kristina ; Divišová, Radka (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with the influence of baristic coffee preparations on the chemical composition of the obtained beverage. Teoretical part of this thesis focuses on coffee growing, processing technology and the chemical composition of coffee beans. In the experimental part were measured samples of espresso coffee, samples prepared by moca pot, flip-drip method, filtrated coffee, samples prepared by french-press technique, vacuum pot samples and boiled coffee. The samples were prepared according to the baristic techniques at first and later with adjusted water and amount of coffee so these methods could be compared with each other. This work focuses on the determination of caffeine and acrylamide content by liquid chromatography, validation of HPLC method, determination of total phenolic content by Folin-Ciocalteu reagent, determination of organic acids by ion chromatography, determination of selected macro and micro elements by inductively coupled plasma in optical emission spectrometry and analysis of aromatic substances using gas chromatography. Based on the processed results and compared methods, it was shown that the moca pot had the greatest influence on the content of caffeine, acrylamide, organic acids and total phenolic substances, and the flip-drip with vacuum pot method had the greatest influence on the content of aromatic substances. From a baristic point of view the highest concentration of caffeine was 3689 mg/l in coffee based on flip-drip method, and concentration of acrylamide was 25,4 mg/l in the coffee based on the same method. The highest value of total phenolic content was determined in moka pot to c = 5,23 g/l. Regarding the mineral representation, the mineral decomposition of coffee beans and espresso were compared, and the highest values were reached by potassium, namely the concentration was 577 mg/l per 1 g of mineralized sample, in the cup of espresso the potassium concentration was 2461 mg/l. The highest content of organic acids was determined in the beverage prepared by moca pot, in terms of selected acids, the largest representation had the succinic acid with the concentration 599,8 mg/l. The highest content of aromatic substances was found in coffee from a moca pot and in coffee by flip-drip method. The biggest part was~made by furfuryl alcohol.
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Biochemistry of polyphenols effects in the treatment of vascular disease
Kondrashov, Alexey ; Štípek, Stanislav (advisor) ; Pecháňová, Olga (referee) ; Matouš-Malbohan, Ivan (referee)
This Ph.D. thesis deals with the deep analysis of polyphenols effects toward vascular disorders. This work provides a number of experimental results of studying both the effects of natural bioactive compounds in red wines and potatoes, and their application to the experiments which includes experimental animal models with spontaneous hypertension. Methods and equipment used in experimental studies allowed us to make several new statements regarding the universal nature of the relationships between the antioxidant capacity and the polyphenolic content in examined foodstuffs. Besides this it is also recognized that food is a source of minerals which also contribute to the total antioxidant capacity and therefore may have influence the endogenous antioxidant enzyme system by providing the essential cofactors. Experimentally we have found that the concentrations of magnesium known for its therapeutic action in wine and red wine extract are comparable to the mineral waters recommended for the treatment and prevention of cardiovascular and metabolic diseases. Moreover, synergistic interactions between selected minerals have been found. The key issue of bioavailability of polyphenols for supporting the idea of the beneficial effects of diet rich in fruits and vegetables toward vascular disease prevention...
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Influence of coffee making process on chemical composition of brewed coffee
Trenzová, Kristina ; Divišová, Radka (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with the influence of baristic coffee preparations on the chemical composition of the obtained beverage. Teoretical part of this thesis focuses on coffee growing, processing technology and the chemical composition of coffee beans. In the experimental part were measured samples of espresso coffee, samples prepared by moca pot, flip-drip method, filtrated coffee, samples prepared by french-press technique, vacuum pot samples and boiled coffee. The samples were prepared according to the baristic techniques at first and later with adjusted water and amount of coffee so these methods could be compared with each other. This work focuses on the determination of caffeine and acrylamide content by liquid chromatography, validation of HPLC method, determination of total phenolic content by Folin-Ciocalteu reagent, determination of organic acids by ion chromatography, determination of selected macro and micro elements by inductively coupled plasma in optical emission spectrometry and analysis of aromatic substances using gas chromatography. Based on the processed results and compared methods, it was shown that the moca pot had the greatest influence on the content of caffeine, acrylamide, organic acids and total phenolic substances, and the flip-drip with vacuum pot method had the greatest influence on the content of aromatic substances. From a baristic point of view the highest concentration of caffeine was 3689 mg/l in coffee based on flip-drip method, and concentration of acrylamide was 25,4 mg/l in the coffee based on the same method. The highest value of total phenolic content was determined in moka pot to c = 5,23 g/l. Regarding the mineral representation, the mineral decomposition of coffee beans and espresso were compared, and the highest values were reached by potassium, namely the concentration was 577 mg/l per 1 g of mineralized sample, in the cup of espresso the potassium concentration was 2461 mg/l. The highest content of organic acids was determined in the beverage prepared by moca pot, in terms of selected acids, the largest representation had the succinic acid with the concentration 599,8 mg/l. The highest content of aromatic substances was found in coffee from a moca pot and in coffee by flip-drip method. The biggest part was~made by furfuryl alcohol.
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Biochemistry of polyphenols effects in the treatment of vascular disease
Kondrashov, Alexey ; Štípek, Stanislav (advisor) ; Pecháňová, Olga (referee) ; Matouš-Malbohan, Ivan (referee)
This Ph.D. thesis deals with the deep analysis of polyphenols effects toward vascular disorders. This work provides a number of experimental results of studying both the effects of natural bioactive compounds in red wines and potatoes, and their application to the experiments which includes experimental animal models with spontaneous hypertension. Methods and equipment used in experimental studies allowed us to make several new statements regarding the universal nature of the relationships between the antioxidant capacity and the polyphenolic content in examined foodstuffs. Besides this it is also recognized that food is a source of minerals which also contribute to the total antioxidant capacity and therefore may have influence the endogenous antioxidant enzyme system by providing the essential cofactors. Experimentally we have found that the concentrations of magnesium known for its therapeutic action in wine and red wine extract are comparable to the mineral waters recommended for the treatment and prevention of cardiovascular and metabolic diseases. Moreover, synergistic interactions between selected minerals have been found. The key issue of bioavailability of polyphenols for supporting the idea of the beneficial effects of diet rich in fruits and vegetables toward vascular disease prevention...
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