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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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Stevia rebaudiana - food and pharmaceutical industry applications
Rücker, Matěj ; Drastík, Martin (advisor) ; Kuchařová, Monika (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Matěj Rücker Supervisor: Ing. Martin Drastík, Ph.D. Title: Stevia rebaudiana - food and pharmaceutical industry applications The first part of this thesis deals with the description of the plant and its substances, the most important are steviolglycosides, especially stevioside and rebaudioside A. In the following chapter, the toxicity and safety are evaluated, which is directly related to the use of stevia and steviolglycosides in food and pharmaceutical practice. In the next part, the utilization in the food industry and connected legislation is described. The harmfulness of the refined sugar is outlined as well. Application in the pharmacy is not so widespread, therefore this chapter deals primarily with the effects of steviolglycosides. Stevia rebaudiana Bertoni and steviolglycosides have great potential to replace sugar and other sweeteners. Due to their beneficial effects, they are very popular among researchers, so we can look forward to their widespread application in food and pharmaceutical industry in the near future. Key words: steviolglycosides, stevioside, rebaudiosede A, sugar, pharmaceutical industry, food industry
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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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Determination of steviol glycosides by HPLC
Hollá, Marcela ; Drastík, Martin (advisor) ; Kubíček, Vladimír (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Marcela Hollá Supervisor: Ing. Martin Drastík, Ph.D. Title of Diploma Thesis: Determination of steviol glycosides by HPLC A new HPLC method was developed and validated for simultaneous detemination of major steviol glycosides stevioside and rebaudioside A in food supplements. Separation took place in hydrophilic interaction chromatography mode on column with core-shell particles. The method was aplicated on analysis of steviol glycosides in products Valosun, SlaDIA, Solia and extract from dried stevia leaves. Isocratic separation was performed using Kinetex 2,6u HILIC 100A, (100 x 2,1 mm; 2,6 µm), Phenomenex analytical column with mobile phase consisted of acetonitrile/0,05 M ammonium formate adjusted with formic acid to pH=3 in ratio 90:10, with flow rate 0,7 ml/min, column temperature set at 30 řC, pressure 19,8 MPa, UV detection at 203 nm and injection volume 1 µl. We compared the results of the analyzes with content of stevioside glycosides declared by the manufacturer. The new developed method allows rapid analysis of food supplements and plant extract containig steviol glycosides. Key words: steviol glycosides, stevioside, rebaudioside A, Stevia rebaudiana Bertoni, high...
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Effect of used sweeteners on sensory properties of fruit jams
PIHLÍK, Pavel
This thesis deals with the sorting and use of sweeteners in the production of fruit spreads. The theoretical part focuses on the sorting of sweetening agents and their classification. Furthermore, it presents procedures of production of fruit spreads and their assortment. The main goal is to compare sensory attributes of jams that I produced according to an assigned recipe, which is described in the practical part of this thesis. These jams were made from regional fruits (strawberries, apricots, sour-cherries) and sweetened with both natural (sucrose, sorbitol, Steviol glycosides) and artificial (sucralose) sweetening agents. The control group of this research were the students and employees of the University of South Bohemia in České Budějovice in the age of 24-60 years. The evaluators filled in a sequence test protocol and a questionnaire for consumers. The results of the sensory analysis were processed into tables and graphs with the aid of statistical methods.
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