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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Avaliação das características estruturais de bolos com redução calórica / Evaluation of structural characteristics of cakes with reduced caloric

Cavalcante, Rosane Souza January 2012 (has links)
CAVALCANTE, Rosane Souza. Avaliação das características estruturais de bolos com redução calórica. 2012. 50 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Departamento de Tecnologia de Alimentos, Programa de Pos-Graduação em Ciências e Tecnologia de Alimentos, Fortaleza-CE, 2012 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-23T13:35:25Z No. of bitstreams: 1 2012_dis_rscavalcante.pdf: 1129788 bytes, checksum: 8f3b16ba9d7215549d158094e9a448d0 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-23T13:35:40Z (GMT) No. of bitstreams: 1 2012_dis_rscavalcante.pdf: 1129788 bytes, checksum: 8f3b16ba9d7215549d158094e9a448d0 (MD5) / Made available in DSpace on 2016-06-23T13:35:40Z (GMT). No. of bitstreams: 1 2012_dis_rscavalcante.pdf: 1129788 bytes, checksum: 8f3b16ba9d7215549d158094e9a448d0 (MD5) Previous issue date: 2012 / The consumption of cakes with calorie reduction is growing, but has presented challenges to be overcome in the formation of its structure when the sugar or fat are replaced by sweeteners, gums, thickeners or fat substitutes. The present study was to investigate the internal characteristics of cakes with calorie reduction and viability of producing the same pattern similar to conventional cake. Initially, we defined the mixing time and mass of fat source to be used in the formulation, using as parameter the specific volume. Next, we determined the pattern of the cake formulation from a factorial experimental design of the simple type, measuring the specific volume and cell count. From this formulation, sucrose and fat were partially substituted for the production of calorie reduced cake. Replacement of sugar was made in proportion of a mixture of xanthan gum (1.5%) and sucralose (1%), while the zein was used to replace fat. In cakes with sugar lowering evaluated the specific volume (VE), the cell count (CC) of the cakes, the apparent viscosity of the mass and its thermal properties by differential scanning calorimetry (DSC). In cakes with reduced fat content, the analyzes were VE, CC and apparent viscosity. It was found that the cake with increased VE was prepared with one hydrogenated vegetable fat and one (1) minute of mixing the dough. The standard formulation was defined as having 155.88 and 28.78 shares of sugar and fat, respectively. As the sugar content decreased (10.00 to 52.17%) were reduced specific volume (1.94 to 0.7 ml / g) and cell counts (from 36.2 to 4.0 cells / cm ²) the cake and the apparent viscosity of the mass (337.56 to 631.40 cP). By reducing the fat content, there were no significant differences between the samples for VE, CC and viscosity, and viable to produce cake with reduced calorie fat replacing up to 46.86%. For the results, it was observed that replacement of sugar contributed more sharply than the replacement of fat in the formation of defects in the structure of the cake. Thermograms of the mass of standard and cakes with reduced sucrose suggested that the presence of sucralose can reduce the starch gelatinization temperature, accelerating the process and causing a compression of the structure during baking, thereby facilitating the coalescing of bubbles dispersed in mass. / O consumo de bolos com redução calórica vem crescendo, mas tem apresentado desafios a serem superados na formação da sua estrutura quando o açúcar ou a gordura são substituídos por adoçantes, gomas, espessantes ou substitutos de gordura. O presente trabalho propôs avaliar as características internas de bolos com redução calórica e a viabilidade de produção do mesmo com características similares ao bolo convencional. Inicialmente, foram definidos o tempo de mistura da massa e a fonte de gordura a ser utilizada na formulação, utilizando-se o volume específico como parâmetro. Em seguida, determinou-se a formulação do bolo padrão a partir de um delineamento experimental do tipo fatorial simples, medindo-se volume específico e a contagem de células. A partir dessa formulação, a sacarose e a gordura foram parcialmente substituídos para a produção de bolos com valor calórico reduzido. A substituição do açúcar foi feita proporcionalmente por uma mistura de goma xantana (1,5%) e sucralose (1%), enquanto a zeína foi usada para substituir a gordura. Nos bolos com redução de açúcar avaliou-se o volume específico (VE), a contagem de células (CC) dos bolos, a viscosidade aparente da massa e as suas propriedades térmicas por meio de calorimetria diferencial de varredura (DSC). Nos bolos com redução do teor de gordura, as análises realizadas foram VE, CC e viscosidade aparente. Verificou-se que o bolo com maior VE foi aquele elaborado com gordura vegetal hidrogenada e 1 (um) minuto de mistura da massa. A formulação padrão foi definida como tendo 155,88 e 28,78 partes de açúcar e de gordura, respectivamente. À medida que o teor de açúcar decresceu (10,00-52,17%) foram reduzidos o volume específico (1,94-0,7 mL/g) e a contagem de células (36,2 – 4,0 cél/cm²) do bolo e a viscosidade aparente da massa (337,56-631,40 cP). Com a redução do teor de gordura, não foram observadas diferenças significativas entre as amostras para VE, CC e viscosidade aparente, sendo viável a produção do bolo com redução calórica substituindo-se a gordura em até 46,86%. Pelos resultados encontrados, foi observado que a substituição do açúcar contribuiu mais acentuadamente que a substituição da gordura na formação de defeitos na estrutura do bolo. Os termogramas das massas dos bolos padrão e com redução de sacarose sugeriram que a presença de sucralose pode reduzir a temperatura de gelatinização do amido, acelerando esse processo e causando uma compactação da estrutura durante o assamento, favorecendo assim a coalescência das bolhas dispersas na massa.
12

Geleia de uva ‘BRS violeta’ convencional e light: produção, caracterização e aceitabilidade / Conventional and light grape BRS violeta jam: production, characterization and acceptability

Vicente, Elisa Lopes Santana [UNESP] 08 September 2016 (has links)
Submitted by Elisa Lopes Santana Vicente null (lisaicj@yahoo.com.br) on 2016-11-04T19:32:57Z No. of bitstreams: 1 Elisa L S Vicente Dissertação.pdf: 1713917 bytes, checksum: 82f2579400078cd372fe44e082af18d9 (MD5) / Rejected by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br), reason: Solicitação do autor on 2016-11-04T19:54:12Z (GMT) / Submitted by Elisa Lopes Santana Vicente null (lisaicj@yahoo.com.br) on 2016-11-04T20:16:41Z No. of bitstreams: 1 Elisa L S Vicente Dissertação.pdf: 1713917 bytes, checksum: 82f2579400078cd372fe44e082af18d9 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-11-10T15:41:29Z (GMT) No. of bitstreams: 1 vicente_els_me_bot.pdf: 1713917 bytes, checksum: 82f2579400078cd372fe44e082af18d9 (MD5) / Made available in DSpace on 2016-11-10T15:41:29Z (GMT). No. of bitstreams: 1 vicente_els_me_bot.pdf: 1713917 bytes, checksum: 82f2579400078cd372fe44e082af18d9 (MD5) Previous issue date: 2016-09-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho visou o desenvolvimento, aceitabilidade, análise nutricional e vida de prateleira de geleia convencional e light de uva cultivar BRS Violeta, utilizando a sucralose como edulcorante. Foram avaliados quatro tratamentos, sendo T1 – Convencional (60 % polpa: 40 % açúcar cristal), T2 - Light 1 (60 % polpa: 30 % açúcar cristal + 10 % sucralose), T3 - Light 2 (60 % polpa: 28 % açúcar cristal + 12 % sucralose), T4 - Light 3 (60 % polpa: 24 % açúcar cristal + 16 % sucralose). Para ocorrer à formação do gel característico da geleia, foram adicionados às formulações, pectina cítrica e ácido cítrico. As geleias foram avaliadas quanto teores de sólidos solúveis, pH, acidez total titulável, açúcar redutor e açúcar total, compostos fenólicos totais, atividade antioxidante total, pigmentos e flavonoides, cor instrumental, análise microbiológica, análise sensorial e avaliação energética, durante um período de 120 dias de armazenamento. Os teores de sólidos solúveis diminuíram durante o tempo avaliado. Houve pequena elevação nos teores de acidez total titulável, principalmente nas formulações light. Os compostos fenólicos e os antioxidantes decaíram durante o armazenamento. As versões de geleia Convencional e Light 2 demonstraram maior estabilidade no tempo armazenado, considerando assim viáveis para fabricação. Não ocorreu contaminação microbiológica nas geleias até os 120 dias de armazenamento, apresentando-se satisfatórias ao consumo. Todas as versões de geleias foram bem aceitas pelo consumidor evidenciando potencial valor comercial. / This work aimed at the development, acceptability, nutritional analysis and shelf life of conventional and light grape jam BRS Violeta using sucralose as a sweetener. We evaluated four treatments: T1 - Conventional (60% pulp: 40% crystal sugar), T2 - Light 1 (60% pulp: 30% granulated sugar + 10% sucralose), T3 - Light 2 (60% pulp: 28% crystal sugar + 12% sucralose), T4 - Light 3 (60% pulp 24% granulated sugar + 16% sucralose). For the formation of the characteristic occurs gel jam were added to the formulations, citric pectin and citric acid. The jams were evaluated for soluble solids, pH, titratable acidity, reducing sugar and the total sugar, total phenolics, total antioxidant activity, pigments and flavonoids, instrumental color, microbiological analysis, sensory analysis and energy assessment for a period of 120 days' storage. The soluble solids decreased during the evaluated time. There was a slight increase in levels of total acidity, especially in light formulations. The phenolics and antioxidants declined during storage. The Conventional and Light 2 jam versions showed greater stability in storage time, thus considering feasible to manufacture. There was no microbiological contamination jam until 120 days of storage, presenting satisfactory consumption. All versions of jams were well accepted by the consumer showing potential commercial value.
13

Vliv použitých sladidel na senzorické vlastnosti džemů z vybraných druhů ovoce / Effect of used sweeteners on sensory properties of fruit jams

PIHLÍK, Pavel January 2017 (has links)
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.
14

Photo Degradation of Cotnaminants of Emerging concern (CECs) under Simulated Solar Radiation: Implications for their Environmental Fate

Batchu, Sudha Rani 25 March 2013 (has links)
Contaminants of emerging concern (CECs) are continuously being released into the environment mainly because of their incomplete removal in the sewage treatment plants (STPs). The CECs selected for the study include antibiotics (macrolides, sulfonamides and ciprofloxacin), sucralose (an artificial sweetener) and dioctyl sulfosuccinate (DOSS, chemical dispersant used in the Deepwater Horizon oil spill). After being discharged into waterways from STPs, photo degradation is a key factor in dictating the environmental fate of antibiotics and sucralose. Photodegradation efficiency depends on many factors such as pH of the matrix, matrix composition, light source and structure of the molecule. These factors exert either synergistic or antagonistic effects in the environment and thus experiments with isolated factors may not yield the same results as the natural environmental processes. Hence in the current study photodegradation of 13 CECs (antibiotics, sucralose and dicotyl sulfosuccinate) were evaluated using natural water matrices with varying composition (deionized water, fresh water and salt water) as well as radiation of different wavelengths (254 nm, 350 nm and simulated solar radiation) in order to mimic natural processes. As expected the contribution of each factor on the overall rate of photodegradation is contaminant specific, for example under similar conditions, the rate in natural waters compared to pure water was enhanced for antibiotics (2-11 fold), significantly reduced for sucralose (no degradation seen in natural waters) and similar in both media for DOSS. In general, it was observed that the studied compounds degraded faster at 254 nm, while when using a simulated sunlight radiation the rate of photolysis of DOSS increased and the rates for antibiotics decreased in comparison to the 350 nm radiation. The photo stability of the studied CECs followed the order sucralose > DOSS > macrolides > sulfonamides > ciprofloxacin and a positive relationship was observed between photo stability and their ubiquitous presence in natural aquatic matrices. An online LC-MS/MS method was developed and validated for sucralose and further applied to reclaimed waters (n =56) and drinking waters (n = 43) from South Florida. Sucralose was detected in reclaimed waters with concentrations reaching up to 18 µg/L. High frequency of detection (> 80%) in drinking waters indicate contamination of ground waters in South Florida by anthropogenic activity.
15

Bacteriostatic Effects of Sucralose on Environmental Bacteria

Omran, Arthur Phillip, Jr. 01 January 2013 (has links)
Sucralose is a zero calorie sweetener developed and manufactured by Tate and Lyle Sweetener Company in the 1980’s. They sell the sweetener compounded with maltodextrin and dextrose under the brand name Splenda®. Sucralose was developed as a low cost artificial sweetener that is non-metabolizable in humans and can withstand changes in pH and temperature. It is not degraded by the waste water treatment process. Since the molecule can withstand heat, acidification and microbial degradation it is accumulating in the environment, and has been found in waste water, estuaries, rivers and the Gulf Stream. The highest concentration of environmental sucralose detected to date is 300 ng/L (Torres et al., 2009). Our lab has isolated six bacterial species from areas that may have been exposed to sucralose, given that sucralose has been detected throughout the aquatic environment (Mead et al., 2009). These isolates were cultured in the presence of sucralose looking for potential sucralose metabolism or growth acceleration. Sucralose was found to be nonnutritive, and we found bacteriostatic effects on all six isolates. This inhibition was directly proportional to the concentration of sucralose exposure. The amount of the growth inhibition appears to be species specific. The bacteriostatic effect may be due to a decrease in sucrose uptake by bacteria exposed to sucralose. We have determined that sucralose inhibits invertase and sucrose permease. These enzymes cannot catalyze hydrolysis or be effective in transmembrane transport of the sugar substitute. As sucralose builds up in the environment we must consider it a contaminant due to its bacteriostatic effect. Sucralose may also destabilize or shift the compositions of the bacterial communities in microenvironments such as the mammalian gut.
16

Odstranění vybraných organických polutantů z vody s využitím pokročilých oxidačních procesů / Removal of selected organic pollutants from water using advanced oxidation processes

Dalajková, Nikola January 2018 (has links)
The aim of this diploma thesis is the determination of selected organic pollutants with a focus on artificial sweeteners in waste water from wastewater treatment plant (WWTP) Modřice and the subsequent degradation of the thus obtained concentrations in model water using advanced oxidation processes (AOP). Two sweeteners were determined, namely sucralose and saccharin found in waste water. Synthetic sweeteners are not sufficiently cleaned in the WWTP and penetrate the environment. Effective processes for removing organic substances, including alternative sweeteners, are AOP processes. These processes are based on reactions of highly reactive hydroxyl radical (OH·), which is produced by many chemical reactions. Generally, they use ozone (O3) and hydrogen peroxide (H2O2). On sampling, wastewater samples were treated with Solid Phase Extraction (SPE) and then evaluated by HPLC/MS (High Performance Liquid Chromatography). In observing the degradation of selected sweeteners, three AOP methods were used: O3/UV, H2O2/UV and O3/H2O2. For each of these methods, the efficiency of degradation of sucralose and saccharin was investigated. From the evaluated data it was found that the most efficient AOP process for removing artificial sweeteners from water is the O3/H2O2 method.
17

Stanovení sladidel a konzervantů v energetických nápojích metodou HPLC / Determination of sweeteners and preservatives in energy drinks by HPLC

Zídková, Anežka January 2019 (has links)
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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