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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 sweetener substitute content in chewing gum
Profousová, Sylvie ; Nábělek, Jakub (referee) ; Diviš, Pavel (advisor)
The bachelor thesis deals with the simultaneous determination of selected sweeteners in chewing gum by high-performance liquid chromatography with ELSD detection. The theoretical part is devoted to the characterization of carbohydrates and their effect on human health, classification, characterization of selected sweeteners and their use. Furthermore, a brief overview of analytical methods by which sweeteners can be determined is given. The experimental part focuses on the selection of a suitable chromatographic column for the simple identification of seven sweeteners (aspartame, acesulfame K, mannitol, maltitol, sucralose and xylitol) and the optimization of the mobile phase composition. It was found that it is not possible to determine all sweeteners by one universal method, however, using an Agilent Hi-Plex Ca column (300 x 7.7 mm) and the mobile phase of acetonitrile:water at 7:93 % v/v, it was possible to determine the concentration of (maltitol, mannitol, sorbitol, sucralose and xylitol). For the analysis of the individual sweeteners, different sample dilutions had to be used or the composition of the mobile phase had to be slightly changed. The concentration of artificial sweeteners in the chewing gum ranged from 0,35 mg/g (sucralose) to 508 mg/g (xylitol).
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Determination of sweetener substitute content in chewing gum
Profousová, Sylvie ; Nábělek, Jakub (referee) ; Diviš, Pavel (advisor)
The bachelor thesis deals with the simultaneous determination of selected sweeteners in chewing gum by high-performance liquid chromatography with ELSD detection. The theoretical part is devoted to the characterization of carbohydrates and their effect on human health, classification, characterization of selected sweeteners and their use. Furthermore, a brief overview of analytical methods by which sweeteners can be determined is given. The experimental part focuses on the selection of a suitable chromatographic column for the simple identification of seven sweeteners (aspartame, acesulfame K, mannitol, maltitol, sucralose and xylitol) and the optimization of the mobile phase composition. It was found that it is not possible to determine all sweeteners by one universal method, however, using an Agilent Hi-Plex Ca column (300 x 7.7 mm) and the mobile phase of acetonitrile:water at 7:93 % v/v, it was possible to determine the concentration of (maltitol, mannitol, sorbitol, sucralose and xylitol). For the analysis of the individual sweeteners, different sample dilutions had to be used or the composition of the mobile phase had to be slightly changed. The concentration of artificial sweeteners in the chewing gum ranged from 0,35 mg/g (sucralose) to 508 mg/g (xylitol).
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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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Chemical mistakes in the light of reality - identification and explanation
Fatka, David ; Šmejkal, Petr (advisor) ; Míka, Luděk (referee)
This thesis deals with widespread, chemically-themed misinformation. The the- oretical part describes psychological effects leading to myth spreading. It also descri- bes the debunking possibilities of such myths and the didactic reasons for misinformation- based work on the high school level. General practical part uses methods of content analysis upon random sample of School educational programmes to prove the usability of misinformation-based work in education. It also summarizes the organisations and resources useful for myth debunking. Specific practical part deals with analysis of chosen suspicious information, their credibility and the possibilities of educational work based on them. The chosen in- formation was the "medicinal" usage of chlorine dioxide solution. Rumors of alkaline diet and alleged harmfulness of aspartame, an artificial sweetener, were also chosen. The way they tend to be presented, none of these claims are backed. In all these cases, multiple unsubstantiated claims were found among proponents of these ideas.
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Porovnání senzorických vlastností džemů slazených steviol-glykosidy a dalšími sladidly
KÜFFNEROVÁ, Nela
The aim of the diploma thesis was evaluation of sensoric attributes of blueberry and current jams sweetened by selected Steviol glycosides and their comparing with other sweeteners. For evaluation of sensoric attributes were used rebaudioside A, stevioside, aspartame, erythritol and sugar beet. Stevia rebaudiana var. Bertoni is a persistent plant, which contains sweetening Steviol glycosides, which have a use in food processing. They are available in the area of EU indicated as E960 since 2011. The most used Steviol glycosides are stevioside and rebaudioside A, which are demarcated with a high sweetness, which could be 200-400 times higher than saccharose. The usage of sweeteners is legislatively allowed, which means it is also allowed to do sensoric analyse and detect perception of added substances in food. These analyses evaluate food with the help of sense - perception. Methodical part of the work contains procedure, used methods for gaining evaluation of data from a sensoric analyse after the degustation of jams, which has taken place with the presence of ten judges - an academic students in the working compartment of University of South Bohemia. Respondents entered their evaluation into protocols, which were prepared in advance. The results of diploma thesis are evaluated by the method of Kramer, which is used for this kind of analyse. The critical scale between 20 and 40 with the value of probability P = 95% was defined according to this method. Evaluation is described with the help of graphs and tables, added with a wordily describtion. Conclusion of analyse of diploma thesis is, that the usage of Steviol glycosides is not most suitable way of sweetening jams. Acceptable valuations of jams containing Steviol glycosides were proven in parameters of colour and aroma. The reasons for less successful evaluation of Steviol glycosides could be due to bad pH of food or badly chosen dosing, without combination of other kinds of sweeteners. The best sensory characteristics traditionally showed sugar beet and aspartame followed by rebaudioside A and stevioside, which were placed on the third and forth place from five used sweeteners. The part of the diploma thesis was an evaluation of questionnaire, where the result was, that asked people preferred fruit ingredient of jams (type of fruit, amount) not their way of sweetening while choosing a jam.
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Low- and nonenergy sweeteners
Trnková, Lenka ; Orsák, Matyáš (advisor) ; Hniličková, Helena (referee)
Low- and no-calorie sugar subtistutes are compounds that provide food with its sweet taste. As the term suggests, they have lower or no food energy and usually are characterized by higher sweetness than sucrose. For that reason, these substances are especially used during the treatment of diabetes mellitus, to reduce the energy content of food or in prevention of dental caries.
Natural sweeteners were discovered a long time ago, during the search for sustenance. For example Stevia was used by South American Natives even before the European conquest of the territory. However, the history of artificial sweeteners is not too significant, because it relates to breaking the laboratory rules. That is how saccharin was invented in 1878.
Sugar substitutes are added to food on purpose, adjusting the taste or extending the shelf life of foods. In the EU, every approved sweetener has got an E-code, which is displayed on the label.
Sugar substitutes can be grouped according to their origin, their nutrition value or their chemical structure. This thesis discusses low- and no-calorie sugar substitutes that can be synthetic or natural. Mentioned synthetic sweeteners typically contain less then 21 kJ per portion. These intensive food additives possess many times the sweetness of sucrose. The main representatives of this group are saccharin, cyclamate, acesulfame K, sucralose and aspartame with its derivatives. The group of natural sugar substitutes constits of substances like erythritol, D-tagatose, trehalose, neohesperidin dihydrochalcone, stevioside and thaumatin.
There are some limitations confirmed by expert studies. For example, patients suffering from diabetes mellitus should mainly use synthetic sweeteners, because of their low nutritional value.
Even though in some states certain sweeteners are forbidden, safety studies say that there are no adverse effects, if the recommended daily intake is respected. Sugar substitutes, therefore, can be considered safe.
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Využití a význam sladidel v potravinách
Čížková, Veronika
Thesis "Use and importance of sweeteners in food" creates a list of commonly used sweeteners, not only in the food industry, but also use of home. Sweeteners are divided into natural and synthetic. Thesis includes informations on the best known and wide spnead natural sweeteners where high consumption risk of dental caries and obesity. Further described are all synthetic sweeteners used in the Czech Republic and the European Union is divided according to the respective categories, including their use in food. Thesis includes a characteristic of diabetes mellistus and phenylketonuria, that the consumption of synthetic sweeteners related.
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Sweeteners (natural and artificial) used in the food industry
PIHLÍK, Pavel
The aim of this work is to introduce the sweeteners which are used in the food industry in the Czech Republic but also in the world. The basic sweetener which is a measure of the other sweeteners is regarded as sugar (sucrose). In this bachelor´s work, I described the history of the production of beet sugar in the Czech Republic, the products which are made of it and also its usage in food industry. Furthermore, I introduce the basic types of sweeteners by which we try to replace the beet sugar. I describe the history, production, characteristics and their usage. These are mainly the natural sweeteners which are divided into the carbohydrate (sucrose, fructose, glucose, honey, lactose and sugar alcohols), non-carbohydrate (stevioside, thaumatin) and artificial align (aspartame, saccharin, cyclamates, acesulfame-K, sucralose).
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