Dissertations / Theses on the topic 'Steviosideo'

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Orientador: Helena Maria Andre Bolini
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Atualmente, há um interesse crescente de consumidores do mundo todo por alimentos e bebidas com menores quantidades de calorias. Neste contexto, a Análise Sensorial é a única forma de se determinar a aceitação e o perfil em relação à aparência, aroma, sabor e textura de alimentos e bebidas, sendo, portanto, uma ferramenta insubstituível. Com base nestes fundamentos, o objetivo do presente projeto foi realizar a determinação de doçura ideal, doçura equivalente de diferentes edulcorantes, análise descritiva quantitativa (ADQ) e análise de aceitação (com mapas de prerência interno, extendido e análise de regressão de mínimos quadrados parciais, Partial Least Squares - PLS) de chocolates adoçados com diferentes edulcorantes (estévia e sucralose) e sacarose (convencional), e com substituto de gordura (concentrado de soro de leite, WPC), comparando seus comportamentos sensoriais, para a obtenção de uma formulação de alta qualidade sensorial. Também foi incluída ao estudo uma amotra diet (em sacarose) comercial. A ADQ e a análise de aceitação foram conduzidas ao longo da estocagem dos chocolates a 20 °C em 0, 3, 6 e 9 meses. A análise de aceitação foi conduzida tanto com consumidores não-diabéticos quanto com diabéticos. Também foram realizadas análises no NCSU Sensory Service Center da North Carolina State University nos Estados Unidos, incluindo análise descritiva, aceitação e conjoint analysis. Foi possível produzir chocolates ao leite diet (em sacarose) e diet (em sacarose)/light (em calorias) com sucralose e estévia como substitutos da sacarose e WPC como substituto parcial de gordura com curvas tempointensidade do gosto doce similares à curva tempo-intensidade do chocolate ao leite convencional de melhor aceitação dentre os testados (43% de sacarose). Houve poucas alterações nos chocolates desenvolvidos em relação ao chocolate convencional. A amostra de chocolate ao leite convencional adoçada com sacarose caracteriza-se mais pelos atributos aroma doce e doçura. As amostras adoçadas com sucralose e sucralose/WPC são caracterizadas, principalmente, pelo atributo sabor de leite em pó (aumentado pelos agentes de corpo lactitol/polidextrose e pelo substituto de gordura WPC). As amostras com estévia se caracterizam pelos atributos amargor e residual amargo. A amostra comercial foi caracterizada por aroma de manteiga de cacau e derretimento na boca. A maioria dos atributos sensoriais das amostras não foi significativamente alterada até o término do estudo aos 9 meses. A comparação das equipes de provadores do Brasil e dos Estados Unidos mostrou que equipes de provadores altamente treinadas usando terminologia padronizada e representativa podem fornecer resultados similares. As amostras convencional e comercial apresentaram as maiores aceitações entre consumidores não-diabéticos. As alterações observadas nos perfis sensoriais não foram suficientes para provocar mudança na aceitação das amostras durante o período de estocagem, o que garante uma vida-de-prateleira efetiva de pelo menos 9 meses. Análise de cluster dividiu os consumidores em dois grupos. As médias de aceitação das amostras convencional e comercial para o grupo 2 foram significativamente maiores. Para o grupo 1, não houve diferença entre as médias de aceitação das amostras convencional, sucralose e sucralose/WPC. As amostras produzidas com sucralose são tão bem aceitas quanto à amostra comercial entre consumidores diabéticos. Todos os chocolates desenvolvidos (diet em sacarose e diet em sacarose/light em calorias, com sucralose ou estévia) apresentaram médias de aceitação estatisticamente maiores entre diabéticos do que entre não-diabéticos. Os consumidores se dividiram principalmente para a amostra convencional e para a amostra comercial. A doçura foi o atributo mais importante para o primeiro grupo enquanto os atributos derretimento na boca e aroma de manteiga de cacau foram mais importantes para o segundo grupo. Estas tendências se mantiveram até o fim do estudo de tempo de estocagem aos 9 meses. Para consumidores dos Estados Unidos, o atributo declaração sobre açúcar é mais importante para diabéticos do que para não-diabéticos enquanto que o tipo de edulcorante e a redução calórica têm a mesma importância para ambos os grupos. Teoricamente, um chocolate com declaração ¿livre de açúcar¿, edulcorante natural e 25% de redução calórica seria a melhor combinação. Os consumidores dos Estados Unidos foram divididos em três grupos, sendo que o grupo 1 se assemelha mais aos diabéticos em geral, e os grupos 2 e 3, aos nãodiabéticos. A principal diferença entre os grupos 2 e 3 está no fato de o grupo 2 ser mais atento ao consumo de calorias. Nos Estados Unidos, convencional, sucralose e sucralose/WPC foram as amostras com melhor aceitação entre não-diabéticos e sucralose, sucralose/WPC e comercial, entre diabéticos, não confirmando o resultado teórico da conjoint analysis. Os consumidores diabéticos são mais receptivos a chocolates ao leite diet (em sacarose) e diet (em sacarose)/light (em calorias) do que consumidores não-diabéticos
Abstract: Nowadays, there is an increasing interest in foods and beverages with smaller amounts of calories. Then, Sensory Evaluation is the most important tool for evaluation of acceptance and sensory characteristics regarding appearance, aroma, flavor and texture of foods. Therefore, objective of the current study was determination of the most accepted sweetness, equi sweet concentration for different sweeteners, quantitative descriptive analysis (QDA) and acceptance testing (using internal and extended preference mappings and PLS regression) of chocolates sweetened with differente sweeteners (steviosídeo and sucralose) and sucrose (conventional), and with whey protein concentrate (WPC) as fat replacer, comparing their sensory characteristics, in order to get a high sensory quality recipe. This research also included a commercial sugra-free sample. QDA and acceptance testing were performed during storage time at 20 °C after 0, 3, 6 and 9 months. Acceptance testing was performed with both non-diabetic and diabetic consumers. In addition, some analyses were carried out at NCSU Sensory Service Center at North Carolina State University, in the USA, including descriptive analysis, acceptance testing, and conjoint analysis. Lab developed prototypes sugar-free and reduced calorie milk chocolates with sucralose or stevioside and WPC as fat replacer presented time-intensity curves similar to most accepted chocolate with sucrose (43%). There were few changes comparing lab developed prototypes to convencional chocolate. Sweet aroma and sweetness were the most important attributes for conventional milk chocolate sweetened with sucrose while milky flavor (increased by bulking agents lactitol/polydextrose and by fat replacer WPC) was the most important attribute for samples sweetened with sucralose and sucralose/WPC. Bitterness and bitter aftertaste were the most important attributes for samples sweetened with stevioside. Regarding commercial sample, cocoa butter aroma and melting rate were the most important attributes. There were not significant changes in most of sensory attributes during 9-month storage time. Comparisons with Brazilian and USA panels showed that highly trained panels using standardized, representative languages can provide comparable results. Conventional and commercial chocolates presented higher acceptance means for non-diabetic consumers. Effects of aging on some sensory characteristics of chocolates were not enough to change consumer acceptance over time, which assures a realistic shelf life for at least 9 months. Cluster analysis presented two groups. Conventional and commercial chocolates presented higher acceptance means for group 2. For group 1, there was no difference between acceptance means for conventional, sucralose, and sucralose/WPC. Diabetic consumers accept samples produced with sucralose so well as they accept commercial sample. All lab developed prototypes presented higher acceptance means among diabetics compared to non-diabetics. Consumers presented preferences especially for conventional sample or for commercial sample. Sweetness was the most important attribute for the first group while melting rate and cocoa butter aroma were the most important attributes for the second group. These results lasted until the end of storage time (9 months). For USA consumers, sugar claim attribute is more important for diabetics than for non-diabetics while sweetener type and calorie reduction attributes have the same importance for both groups. A chocolate with sugar-free claim, natural sweetener and 25% calorie reduction would be theoretically the best combination. USA consumers were segmented in 3 clusters and cluster 1 was more similar to diabetics while clusters 2 and 3 were more similar to non-diabetics. The main difference between clusters 2 and 3 is consumers in cluster 2 are more concerned about calorie consumption. In the USA, conventional, sucralose, and sucralose/WPC were the most accepted samples among nondiabetics and sucralose, sucralose/WPC, and commercial were the most accepted samples among diabetics, which did not confirm theorical results of conjoint analysis. Diabetic consumers are more accepting than non-diabetic consumers of diabetic and diabetic/reduced calorie milk chocolates
Doutorado
Consumo e Qualidade de Alimentos
Doutor em Alimentos e Nutrição

The steviolglycosides are the natural, sweet substances from Stevia rebaudiana Bertoni. It affect human health positively and its sweetness is 300x stronger than the sweetness of sucrose. That's why it's used to sweetening the commercial products. Because of its potential properties it's good to have an appropriate method to isolate it. High performance liquid chromatography ( HPLC) is based on the separation of analyte between two immiscible phases with high pressure pump and appropriately chosen stationary phase in the column. Than the analytes come out from the column in different retention times. This master´s thesis follows up selection of the best HPLC system for isolation of the main steviolglycosides and its analysis in commercial products. In the theoretical part of the thesis is described the origin, basic characteristics, botanical description, cultivation and affect to the human health of Stevia rebaudiana Bertoni and its use in food industry. There are also concisely characterized the sweet substances contained in the plant, so called steviolglycosides. Than there are given the theoretical basics of high performance liquid chromatography, HPLC instrumentation and its specific applications at sleviolglycosides with the basic chromatographic parameters. The object of the first experimental part was to research the optimum conditions for time and separation effective chromatographic analysis and select the best chromatographic system for isolation of steviolglycosides. In the second experimental part, I have compared and defined the main steviolglycosides (stevioside, rebaudioside A) in nine selected products, commercially available in Czech republic, with the best chromatographic method. In these products was the contain of the stevioside or rebaudioside A confirmed or refused.

This diploma thesis deals with sweet substances from Stevia rebaudiana and with their determination in beverages. The ambition was to adjust the separation method for major steviol glycosides (stevioside and rebaudioside A) by HPLC so as to be fast and effective enough, too. In experimental part was successfully developed the separatin method, so it is possible to determine the steviol glycosides and conservation substances, specifically benzoic and sorbic acid (eventually their sodium or potassium salts). At first, for analysis was used monolithic column, on which stevioside and rebaudioside A weren´t separated. Other analyses were performed on column Ascentis express C18 (150 x 4.6; 2.7 µm). The most suitable separation method was performed by mobile phase made up with 29:71 v/v mixture of acetonitrile and acetate buffer (with pH 4.2). The flow rate was 0.28 ml/min and the column temperature was kept constant at 50 °C. The analysis of steviol glycosides and conservation substances with these condition was verified on the samples of real beverages.

Artificiella sötningsmedel används istället för vanligt socker i tandkräm men vanligast är att de används i lättprodukter samt livsmedel utan tillsatt socker som exempelvis läsk. Användandet av sötningsmedel ökar och det beror dels på att det är lämpligt för diabetespatienter och överviktiga men det är även populärt bland den övriga befolkningen då det inte innehåller någon energi. Det första artificiella sötningsmedlet upptäcktes redan 1879 och sedan dess har flera olika artificiella sötningsmedel påfunnits. När sötningsmedlen introducerades på marknaden uppkom misstankar om att de skulle ha cancerogena bieffekter. Nu har det klargjorts vad de har för inverkan på hälsan, och nu ligger fokus på om sötningsmedel påverkar miljön och hur. De sötningsmedel som undersöks i den här studien är acesulfamkalium, aspartam, steviosid samt sukralos. Syftet med studien är att se om dessa sötningsmedel bryts ner av ultraviolett ljus för att få en uppfattning om sötningsmedlen kan ha en negativ verkan på miljön. Laborationen utfördes genom att bestråla prover med UV-ljus, efter bestrålningen undersöktes proverna för att se om mängden substans minskat, genom att använda analysinstrumentet UV-spektrofotometer. Sju mättider valdes ut och för vardera tidpunkt och ämne utfördes i tre replikat. Resultaten analyserades och redovisas med hjälp av diagram och tabeller, resultaten blev inte som jag förväntade mig. Resultaten visade inte på någon nedbrytning av sötningsmedlen då de belystes med UV-ljus i den här studien. Resultat förklaras med hjälp av andra studier på samma område och en sak alla är överens om är att det är ett viktigt område som behöver mera forskning.

Comparative studies of taste perception have found that primates may differ markedly in their sensitivity for substances perceived as sweet by humans. These findings raise questions about the reason that may underlie these differences in sweet-taste sensitivity between species. The aim of the present study was to assess the taste responsiveness of chimpanzees (Pan troglodytes verus) to seven substances tasting sweet to humans and to compare the results with those of other primate species. Using a two-bottle preference test (1 min) I found that the taste preference thresholds of the chimpanzees for five food-associated carbohydrates ranged between 20-30 mM for sucrose, 20-50 mM for fructose, 60-80 mM for glucose, 50-80 mM for maltose, and 30-80 mM for lactose. Taste preference thresholds for two steviol glycosides ranged from 0.04-0.05 mM for stevioside, and 0.03-0.05 mM for rebaudioside A. The chimpanzees displayed clear preferences for all sweet-tasting substances presented. In line with data obtained in other primates, the taste preference threshold of the chimpanzees for sucrose was lower compared to the other carbohydrates presented and the taste preference thresholds for stevioside and rebaudioside A were lower compared to sucrose. In general, the taste sensitivity of the chimpanzees fell into the range of data reported in other nonhuman primate species. Interestingly, the taste preference thresholds of the chimpanzees reported here are similar to the taste detection thresholds obtained in humans, despite the fact that the former are only a conservative approximation of an animal’s taste sensitivity. This suggests that chimpanzees may be as sweet-taste sensitive as humans.

SyfteSyftet med denna laborativa pilotstudie in vitro var att undersöka hur den mikrobiella sammansättningen och pH i den orala biofilmen påverkades vid upprepad exponering för Stevia (steviosid och rebaudiosid A), sackaros eller en kombination av reb A och sackaros. Ett ytterligare syfte var att studera om isolat av orala bakterier kunde metabolisera reb A i buljongkultur. Material och metodBiofilmer från tre personer blev exponerade för 0,025 % steviosid, 0,025 % reb A eller 10 % Todd Hewitt (TH) under 15 minuter tre gånger dagligen i fyra dagar. Artbestämning gjordes i början och slutet av försöken. Biofilmerna exponerades för 0,025 % reb A och 10 % sackaros eller en kombination av dessa varefter pH-värdet mättes. Vidare studerades 23 bakteriestammar avseende förmåga att metabolisera 0,025% respektive 0,5% reb A. ResultatStreptokocker dominerade i samtliga biofilmer vid försökets slut oavsett om de exponerats för steviosid, reb A eller enbart TH. En pH-sänkning kunde ses hos biofilmerna som enbart blivit exponerade för sackaros eller för en kombination av sackaros och reb A. Däremot kunde endast en marginell pH-sänkning observeras efter exponering för enbart reb A. Ingen av de enskilda bakteriestammar som studerades kunde metabolisera reb A.SlutsatsIngen större skillnad i biofilmens bakteriesammansättning kunde ses efter upprepad exponering för steviosid eller reb A i förhållande till TH.Upprepade exponeringar av reb A i kombination med sackaros gav en liknande pH-sänkning som enbart sackaros, dock sågs ingen pH-sänkning efter exponering för enbart reb A. Enskilda bakteriestammar kunde inte metabolisera reb A.
AimsIn this in vitro laboratory pilot study, the effect on the microbial composition and pH of the oral biofilms after repeated exposure to Stevia (stevioside and rebaudioside A), saccarose or a combination, was investigated. Another aim was to study whether isolate of oral bacteria were able to metabolise reb A in broth bacteria culture.Material and MethodBiofilms from three adult individuals were repeatedly exposed to 0,025% stevioside, 0,025% reb A or 10% Todd Hewitt (TH). Samples were taken at the beginning and at the end of the experiment for cultivation and bacterial identification.Biofilms were exposed to 0,025% reb A and 10% saccharose, either separately or combined, followed by a pH-measurement. Furthermore, 23 bacterial species were studied in regards to ability to metabolize reb A. ResultsAll biofilms were dominated by Streptococcus regardless of whether they were exposed to stevioside, reb A, or TH. A pH-decrease was seen in biofilms exposed to saccharose or a combination of saccharose and reb A. However, only minor changes were noted after exposure to reb A.None of the species studied were able to metabolize reb A.ConclusionNo major differences in the bacterial composition of the biofilms were seen after repeated exposure to stevioside or reb A compared to TH.No pH-decrease after repeated exposure to reb A was noted. Exposure to reb A combined with saccharose resulted in a pH-decrease similar to exposure to saccharose. The bacterial species tested in this study were not able to metabolise reb A.

Charles University Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Karolína Dalecká Supervisor: Ing. Martin Drastík, Ph.D. Title: SPE in steviol glycosides analysis In the first part of this diploma thesis, the solid phase extraction method is described. The topics like the workflow, usability of sorbents and their formats and interactions with analytes are covered. The second part of this thesis is focused on utilization of solid phase extraction on samples containing steviol glycosides. An overview of solid phase sorbents their forms; solvents used for extraction and elution of steviol glycosides is provided in the discussion section at the very end of this work. Taking into account the fact that stevia has been used more and more on the European market in recent years, and is found in more food and other products, the frequency of determination of steviol glycosides and the use of solid phase extraction is on rise. The most commonly extracted samples include food products with steviol glycosides used as sweeteners or extracts of dried stevia leaves. The main sorbents used for solid phase extraction include silica gel with octadecyl and divinylbenzene-co-vinylpyrrolidine copolymer. This type of extraction is most often connected with high...

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...

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

博士
國立屏東科技大學
食品科學系
94
Stevioside, a glycoside contained in the leaves of Stevia rebaudiana Bertoni (Compositae) used as popular sweetner, was employed to screen the effect on insulin resistance of rats induced by a diet containing 60 % fructose. Oral administration of stevioside decreased the plasma glucose concentration in a dose-dependent manner in rats received 4-week fructose-rich chow. In addition, insulin action on glucose disposal rate was measured using the glucose-insulin index, the product of the areas under the curve of glucose and insu- lin during the intraperitoneal glucose tolerance test. Oral administration of stevioside (5.0 mg/kg) into fructose fed rats for 90 min reversed the value of glucose-insulin index, indicating stevioside has the ability to improve insulin sensitivity in this insulin resistant animal model. Time for the loss of plasma glucose lowering response to tolbutamide (10.0 mg/kg, i.p.) in fructose fed rats was also markedly delayed by the repeated oral intake of stevioside three times daily, as compared to the vehicle-treated group. The plasma glucose lowering activity of tolbutamide is introduced to depend on the secretion of endogenous insulin and this is widely used as an indicator of insulin resistance formation. Thus, it provided the supportive data that repeated oral administration of stevioside delayed the development of insulin resistance in high fructose feeding rats. Increase of insulin sensitivity by stevioside was further identified using the plasma glucose lowering action of exogenous insulin in streptozotocin-induced diabetic rats (STZ-diabetic rats). Oral administration of stevioside at 0.2 mg/kg three times daily into STZ-diabetic rats for 10 days made an increase of the responses to exogenous insulin. Taken together, it showed that oral administration of stevioside improves insulin sensitivity and it seems suitable to use as an adjuvant for diabetic patients and/or the subject who consumed large amounts of fructose. In an attempt to develop new substances for handling diabetes, Hon-Chi was employed to screen the antihyperglycemic action in STZ-diabetic rats. The mandarin Hon-Chi is the red yeast rice fermented with Monascus pilous and Monascus purpureus. Oral administration of Hon-Chi decreased the plasma glucose of STZ-diabetic rats in a dose-dependent manner from 50 mg/kg to 350 mg/kg. Similar treatment of Hon-Chi also lowered the plasma glucose in normal rats as effective as that produced in STZ-diabetic rats. In addition, oral administration of Hon-Chi at the highest dose (350 mg/kg) attenuated the elevation of plasma glucose induced by an intravenous glucose challenge test in normal rats. Moreover, the mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) in the liver from STZ-diabetic rats were reversed in a dose-dependent manner by the repeated oral intake of Hon-Chi three times daily for 2 weeks. Otherwise, hyperphagia in STZ-diabetic rats was markedly reversed by similar repeated treatment of Hon-Chi. The obtained results suggest that oral administration of Hon-Chi could decrease hepatic gluconeogenesis to lower plasma glucose in diabetic rats lacking insulin. Thus, it also is suitable to use as an adjuvant for diabetic patients.

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.

博士
臺北醫學大學
藥學系
92
I.The medicinal preparations based on the modification natural compounds frequently exceeded the native substances in the activity. In this connection investigation into the chemistry and pharmacological properties of bioactive natural substances has become an important direction in the modern bioorganic and medicinal chemistry. The renewed interest in Stevioside reflects the general trends observed in medicine were remedies of the natural origin are finding an increasing application. Stevioside 3, an ent-kaurene glycoside extracted from Stevia rebaudiana Bertoni (Compositae), is used not only as a food additive for sweetening purposes but for anti-hypertensive, anti-hyperglycemia, anti-inflammatory and suppressed the tumor-promoting effects. Thus, stevioside analogues would be of interest to exploit its potential activities and to establish structure activity relationships. Twenty-two novel steviolbioside analogues and their related steviol and isosteviol dimers are prepared using aliphatic alkylamines and alkyldiamines by the activated esters method (PyBOP coupling). The structures of these compounds were established using spectroscopic analysis including IR, 1H NMR, 13C NMR, FABMS, and LC/MS/MS(ESI). The results obtained, however, strongly confirm the influence of amine nucleophilicity, basicity, the steric hiderance and reaction termerature somewhat influenced the formation of steviolbioside carboxamides. Glycoside sugars did not seem to perturb the coupling reactions of carboxamides. The cytotoxicities of all of the synthesized compounds to cancer cell lines and human embryo lung cells are examined. These results suggest that the cytotoxic effect on cancer cells involves many different structural domains of the compounds. The antibacterial activities of these synthesized compounds were also detected using modified microplate antibiotic susceptibility testing method (MMAST) with both gram-positive and gram-negative bacteria. The results indicated that compound 2t is more-potent antibacterial effect than penicillin G on Bacillus subtilis (BCRC 10029). Prior to this study, the available information on dimerization and glycodic moiety of SAR indicated that molecular recognition involved specific receptor interactions. We propose that the various chain lengths can change the binding of ligands to their respective receptors and thereby improve biological activities. II.Cantharidin is found in Mylabris caraganae and various other insects and has an extremely high potency with antitumor properties, causes leukocytosis and inhibition of protein phosphatase activity. However, it is rarely employed to the therapeutic treatment owing to the irritation and vesication side effects and as toxic properties. In our previous studies, a series of N-thiazolyl and thiadiazolyl cantharidinimides were prepared starting from cantharidin with various amines in triethylamine by heating to ca. 200 oC, and the analogues with better solubility showed cytotoxicity against human hepatocellular carcinoma cell lines, which encouraged us to prepare cantharidinimide derivatives. This present study, the aliphartic cantharidinimide 3a—3c is synthesized and the cytotoxicity of aliphartic, aryl, and pyridyl of twenty-one derivatives and cantharidin is investigated against Hep G2 and HL-60 cell lines. Cytotoxicity tests shows that Cantharidin 1 is more toxic and exhibits greater cytotoxicity, while synthesized cantharidinimides is less toxic but also exhibits inhibitory effects. It can be suspected that the decrease with the inductive electron negative effect of the N-substituted group will decrease the yield and increase the cytotoxicity. The results suggest that the presence of a nitropyridyl or nitrophenyl moiety display strong inhibitory effects on both cell lines as did cantharidin.

The theoretical part of the diploma thesis deals with cultivation of the plant Stevia rebaudiana. This plant is 300x sweeter than sucrose. It is often used as a compensation for sugar sweetener, suitable for diabetics and people who suffer from overweight. There is processed the characteristics of the plant, botanical description, conditions of cultivation and chemical composition. There are described the methods of determination of steviol glycosides. The practical part elaborates on a sensorical analysis. This analysis has two parts. The first part is the evaluation of stevia concentrates with the flavour of aronia, sour cherry and beetroot and stevia powder in 10 milk products bought in supermarkets. The second part deals with the evaluation of black tea sweetened with few different easily available sorts of sweetening products. The currently valid legislative in the area of the Czech Republic allows the food industry to use steviol glycosides of high purity under the name E960. The use of the plant stevia or its parts as food isn't enabled.

Relatório de Estágio do Mestrado Integrado em Ciências Farmacêuticas apresentado à Faculdade de Farmácia
O consumo excessivo de açúcar tem-se vindo a tornar num dos maiores problemas de saúde pública em todo o mundo, sendo o grande causador de doenças como a Diabetes mellitus tipo 2 e a obesidade, pelo que a necessidade de se encontrar uma alternativa que leve à diminuição do seu consumo se tornou uma prioridade. Os glicosídeos do esteviol têm origem na planta Stevia rebaudiana Bertoni, originária da América do Sul, frequentemente encontrada na zona da fronteira entre o Paraguai e o Brasil. Esta planta é utilizada por povos nativos do Paraguaia há mais de 1500 anos devido ao seu sabor doce e às suas propriedades medicinais. Os glicosídeos do esteviol, extraídos da folha de Stevia rebaudiana, são edulcorantes não calóricos que, para além de conferirem o sabor doce, podem ainda trazer benefícios à saúde humana. Pretende-se então fazer uma análise critica aos glicosídeos de esteviol enquanto edulcorante, avaliar a segurança do consumo diário deste aditivo alimentar, o seu potencial para causar toxicidade aguda ou cónica (genotoxicidade, carcinogenicidade e toxicidade reprodutiva), ou o seu potencial alergénico. É a ainda importante averiguar quais as vantagens que podem advir do seu consumo, bem como as suas alegadas propriedades medicinais (anti-hipertensor, anti-diarreico..). Na Europa, o extrato altamente purificado de glicosídeos do esteviol foi aprovado pela Comissão Europeia há apenas alguns anos, em 2011, no entanto, o seu crescimento foi extremamente rápido, sendo possível encontrar inúmeros produtos aditivados com esta substância à venda no mercado, sendo os refrigerantes os produtos com maior destaque.
The excessive consumption of sugar has become one of the greatest threats to public health in the world and is one of the major cause of diseases like Type 2 Diabetes mellitus and obesity, so the need to find an alternative that leads to a decrease consumption of sugar has become a priority. Steviol glycosides come from the Stevia rebaudiana Bertoni plant, which is native to South America, often found on the border between Paraguay and Brazil. This plant is used by the natives of Paraguay for more than 1500 years because of it sweet taste and medicinal properties. Steviol glycosides, extracted from Stevia rebaudiana leaf, are non-caloric sweeteners that, in addition to provide a sweet taste, it can also bring benefits to human health. It is intended to make a critical analysis to the glycosides of steviol as a sweetener, to evaluate the safety of the consumption of this food additive on a daily basis, its potential for acute or chronic toxicity (genotoxicity, carcinogenicity and reproductive toxicity), or its allergenic potential.It is also important to investigate the advantages that can come of its consumption, as well as its alleged medicinal properties (antihypertensive, anti-diarrheal...). In Europe, the highly purified glycosides extract of stevioside was approved a few years ago, in 2011 by the European Commission however, its growth was extremely fast and it is already possible to find numerous products added with this substance for sale in every supermarkets, being the soft drinks the most outstanding.