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Caffeine use in patients with eating disorders
Hofmannová, Zuzana ; Dostálová, Veronika (advisor) ; Minařík, Petr (referee)
Background: Caffeine is a commonly used stimulant that is not dangerous in normal doses in healthy individuals. Patients with eating disorders tend to overuse caffeine and excessive intake may increase the risk of both somatic and mental health complications. Aims: The main aim of this thesis was to provide a comprehensive review of the literature on the sources and effects of caffeine and to analyse specific aspects of caffeine use in the psychiatric population with eating disorders. The thesis focuses primarily on the motivation for use in different eating disorders and the impact on physical and mental health. The second aim was to discuss the possible clinical relevance of the topic and to propose a specific tool for health professionals to screen for caffeine use and the implications of this issue in the treatment of this specific group Methods: The thesis is theoretical in the form of a search of the current state of literature and research from academic sources. Based on the information obtained, a questionnaire was designed to assess caffeine consumption and reasons for its use in patients with eating disorders. Results: An analysis of the literature shows that psychiatric patients often abuse caffeine products, and for those with eating disorders, the main reason for use is to suppress...
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Development of a new type of energy drinks containing natural active components
Vysoká, Marie ; Němcová, Andrea (referee) ; Skoumalová, Petra (advisor)
The aim of this thesis is the development and preparation of a new energy drink. The theoretical part of the thesis focuses on the comparison of the drinks available in market, the presentation of the main active ingredients and the proposal of enriching the new energy drink. It also describes the possibility of using an encapsulation and the method used to determine specific compound in energy drink or encapsulated particles. In the experimental part of the work, at the beginning, the main content of energy drinks were characterized, for instance caffeine, sugar, polyphenol and vitamin C. Subsequently the energy drink based on selected types of loose teas that were enriched with the encapsulated extract of acai, acerola, maca, goji and ginseng was designed. All extracts contained large amounts of polyphenols and antioxidants. In addition, acerola extracts contained very high amounts of vitamin C. Two types of particles, alginate particles and liposomes were prepared for encapsulation. For all particles, encapsulation efficiency, size, stability, and antioxidant activity were determined. Long-term stability was then monitored within three months. The particles were also exposed to artificial gastric, pancreatic and bile juice. All tested particles showed very good encapsulation efficiency. In terms of long-term storage stability in an aqueous environment. Particularly liposome particles, which also showed high stability by zeta potential measurement, were suitable. On the contrary, in case of alginate particles, when stored in an aqueous medium, the release of active substances occurred. Finally, an energy drink was created and subjected to sensory analysis. The best energy drink was based on black or green tea with alginate particles acai, goji and ginseng.
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Determination of sweeteners and preservatives in energy drinks by HPLC
Zídková, Anežka ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This master´s thesis is focused on simultaneous determination of sweeteners and preservatives in energy drinks by liquid chromatography coupled with DAD and ELSD detection. The method was optimized for determination of aspartame, acesulfame K, saccharin, sucralose, steviol glycosides, benzoic acid and sorbic acid. Analyses were carried out on the Poroshell 120 EC-C18 column (4.6 x 150 mm, 2.7 m, Agilent) using mixture of methanol, acetone and water with formic acid and trimethylamine as a gradient mobile phase at a flow rate 0,5 mL•min-1. Validation parameters were determined (limit of detection, limit of quantification, repeatability and recovery). The validated method was applied on real samples.
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Characterization of beverages and food supplements containig caffeine
Patočková, Klára ; Pekař, Miloslav (referee) ; Márová, Ivana (advisor)
This master thesis is focused on characterization of some energy drinks and formulation of their modified composition. The theoretical part was focused on summary of energy drinks and some of their natural components - guarana, goji as well as on techniques of encapsulation. In the experimental part concentrations of caffeine, vitamin C, polyphenols and carbohydrates in commercially purchased drinks was evaluated. Subsequently, three kinds of particles (particles with caffeine, particles with guarana and particles with guarana and goji) by 6 different techniques were prepared. The efficiency of encapsulation was determined by HPLC/UV-VIS (caffeine, vitamin C) and by spectrophotometry (phenolics). Stability of the particles was followed in real food and in a model physiological environment of artificial digestive juices. Size of prepared particles was determined by dynamic light scattering. In this work it was found that particles with best activity and stability were obtained by encapsulator. For manual particles the best results were found in the liposome particles. Liposomes exhibited the smallest particle size, the highest efficiency encapsulation, excellent stability in real food and juices and the best value of zeta potential.
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Development of new type of energy drinks based on coffee with active substances
Dudrová, Markéta ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with development and preparation of new energy drinks with active plant component in free and encapsulated form. The theoretical part is focused on characterization of the energy drinks, their components and properties. The experimental part deals with the preparation of plant extracts, their characterization and subsequent encapsulation into liposome particles. All particles were determined for size, colloidal stability, long-term stability, antioxidant activity and encapsulation efficiency. Energy drinks based on various types of coffee were prepared and enriched with free or encapsulated guarana, goji, matcha or cocoa extract. In prepared energy drinks the content of caffeine, sugar, phenolics and antioxidant aktivity was monitored. Finally, selected energy drinks were subjected to sensory analysis, where appearance, color, smell and taste were evaluated.
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Encapsulation of active and complementary components of energy drinks
Kšenžighová, Petra ; Vysoká, Marie (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis was focused on the development of an energy drink containing plant powders and active substances in both free and encapsulated form. Green barley, matcha tea, moringa and young wheat were chosen as plant powder samples. The theoretical part describes the active and complementary constituents of energy drinks, their nutritional properties and impact on health. The encapsulation itself is also described in this section. In the practical part, extracts from plant powders were prepared, in which bioactive substances were determined, namely total phenolic content, flavonoids and antioxidants. The total content of carotenoids and chlorophylls was also determined in the samples. By juicing the fruit, fruit juices were obtained in which vitamin C and antioxidant content were subsequently determined. Liposome particles differing in soy and sunflower lecithin were prepared containing caffeine, taurine and vitamin C. Encapsulation activity, colloidal stability, size and long-term stability were determined in the particles. All prepared particles, with the exception of encapsulated taurine in sunflower particles, were stable. Finally, a sensory analysis was performed, where respondents evaluated the prepared energy drinks in terms of taste, consistency, smell and appearance. Based on the results of measurements, a new energy drink was designed.
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Consumption of energy drinks by pupils at a selected lower secondary school
Kunešová, Klára ; Thorovská, Alena (advisor) ; Zvírotský, Michal (referee)
Consumption of energy drinks by pupils at a selected lower secondary school ABSTRACT The presented bachelor's thesis deals with the issue of energy drinks consumption by pupils at a selected lower secondary school. The concept energy drink is described in the introduction to the theoretical part of the thesis. Furthemore, the theoretical part of the thesis is dedicated to the description of the most common components in energy drinks. Subsequently, the thesis focuses mainly on the amount of sweeteners in selected energy drinks on the Czech market. In the practical part of the thesis there is a questionnaire survey investigated among pupils at the lower secondary school in Český Brod, where their general awareness of energy drinks is ascertained. KEYWORDS Energy drinks, vitamins, taurine, caffeine, sweeteners, questionnaire survey, lower secondary school, consumer behaviour
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Encapsulation of active and complementary components of energy drinks
Kšenžighová, Petra ; Vysoká, Marie (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis was focused on the development of an energy drink containing plant powders and active substances in both free and encapsulated form. Green barley, matcha tea, moringa and young wheat were chosen as plant powder samples. The theoretical part describes the active and complementary constituents of energy drinks, their nutritional properties and impact on health. The encapsulation itself is also described in this section. In the practical part, extracts from plant powders were prepared, in which bioactive substances were determined, namely total phenolic content, flavonoids and antioxidants. The total content of carotenoids and chlorophylls was also determined in the samples. By juicing the fruit, fruit juices were obtained in which vitamin C and antioxidant content were subsequently determined. Liposome particles differing in soy and sunflower lecithin were prepared containing caffeine, taurine and vitamin C. Encapsulation activity, colloidal stability, size and long-term stability were determined in the particles. All prepared particles, with the exception of encapsulated taurine in sunflower particles, were stable. Finally, a sensory analysis was performed, where respondents evaluated the prepared energy drinks in terms of taste, consistency, smell and appearance. Based on the results of measurements, a new energy drink was designed.
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Development of new type of energy drinks based on coffee with active substances
Dudrová, Markéta ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with development and preparation of new energy drinks with active plant component in free and encapsulated form. The theoretical part is focused on characterization of the energy drinks, their components and properties. The experimental part deals with the preparation of plant extracts, their characterization and subsequent encapsulation into liposome particles. All particles were determined for size, colloidal stability, long-term stability, antioxidant activity and encapsulation efficiency. Energy drinks based on various types of coffee were prepared and enriched with free or encapsulated guarana, goji, matcha or cocoa extract. In prepared energy drinks the content of caffeine, sugar, phenolics and antioxidant aktivity was monitored. Finally, selected energy drinks were subjected to sensory analysis, where appearance, color, smell and taste were evaluated.
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Determination of sweeteners and preservatives in energy drinks by HPLC
Zídková, Anežka ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This master´s thesis is focused on simultaneous determination of sweeteners and preservatives in energy drinks by liquid chromatography coupled with DAD and ELSD detection. The method was optimized for determination of aspartame, acesulfame K, saccharin, sucralose, steviol glycosides, benzoic acid and sorbic acid. Analyses were carried out on the Poroshell 120 EC-C18 column (4.6 x 150 mm, 2.7 m, Agilent) using mixture of methanol, acetone and water with formic acid and trimethylamine as a gradient mobile phase at a flow rate 0,5 mL•min-1. Validation parameters were determined (limit of detection, limit of quantification, repeatability and recovery). The validated method was applied on real samples.
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