The effect of sweeteners on fruit flavor perception was studied through the use of fruitiness power functions for unsweetened and sweetened model systems. In the first part of the study, two isosweet concentrations of aspartame and sucrose were determined and combined with five concentrations of orange and strawberry flavorants. Fruitiness power functions were developed and compared to determine the effect of each sweetener on the fruit flavor. For the second part of the study in the first experiment, one isosweet concentration of sucrose, aspartame, acesulfame-K and 1:1 blended APM/Ace-K was combined with five concentrations of each of three orange flavorants. Fruitiness power functions were developed and compared to determine how each sweetener effected the fruit flavor of each flavorant. The second experiment addressed the question of whether or not subjects associated sweet taste with fruitiness or if there was an actual change in the volatile composition of the aroma between the unsweetened reference and the sweetened solutions. Fruit aroma of the middle concentration of each flavorant sweetened with the four sweeteners was compared to the corresponding unsweetened reference. Enhancement of fruitiness was observed in the aspartame sweetened systems at low flavor levels. The power function slopes of both flavorants were lowered by the addition of aspartame which resulted in a slower rate of growth in fruitiness perception with the addition of flavorant to the system. In both the orange and strawberry flavored systems the aspartame sweetened solutions were rated higher in fruitiness than the sucrose sweetened solutions. The enhancement was more pronounced in the orange flavored system, suggesting a flavorant effect. The sweeteners affected the fruitiness perception of the three orange flavorants in different magnitudes but the patterns were similar. The three fruitiness slopes were all lowered by the addition of each sweetener. Flavor enhancement was greatest in flavor 1 sweetened with aspartame or aspartame/acesulfame-K. The higher relative placement and low slope of the fruitiness power functions in aspartame sweetened systems caused the enhancement effect to be greatest over the lower concentrations of each flavorant. In the second experiment, the fruit aroma of aspartame sweetened solutions in flavor 1 was significantly higher than the other sweetened solutions. The fruit aroma of the second and third flavorants was not significantly changed by the sweeteners. / Graduation date: 1992

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-03T13:51:14Z No. of bitstreams: 1 vivannazaretholiveirafernandes.pdf: 1261363 bytes, checksum: 29d944a0020a492413570231b2056b50 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-13T13:34:27Z (GMT) No. of bitstreams: 1 vivannazaretholiveirafernandes.pdf: 1261363 bytes, checksum: 29d944a0020a492413570231b2056b50 (MD5) / Made available in DSpace on 2017-05-13T13:34:27Z (GMT). No. of bitstreams: 1 vivannazaretholiveirafernandes.pdf: 1261363 bytes, checksum: 29d944a0020a492413570231b2056b50 (MD5) Previous issue date: 2010-02-25 / Foi desenvolvida inovadora metodologia para a separação e quantificação simultânea de aspartame, ciclamato, sacarina e acesulfame-K por eletroforese capilar, com detecção direta e indireta UV, tempo de análise de aproximadamente 6 minutos e sem derivatização da amostra. Como o ciclamato possui baixa absortividade, foi utilizado um sistema de eletrólito adicionado de um cromóforo, possibilitando a detecção indireta deste analito. O comprimento de onda foi escolhido considerando-se uma absortividade intermediária entre o cromóforo do eletrólito, o aspartame, sacarina e acesulfame-K. Após teste de alguns cromóforos, o ácido benzóico foi selecionado como o mais adequado. Um ponto a ser considerado é que matrizes de alimento possuem ácido benzóico em sua constituição, sendo utilizado como conservante. Apesar dele ainda ser detectado no sistema de eletrólito e condições de análise propostos, sua quantificação não pode ser realizada, devido sua inclusão no eletrólito, demonstrando indícios de falta de ajuste do modelo linear, com 95% de confiança. A condição ótima para separação eletroforética foi obtida mediante uso de planejamento fatorial 32. A otimização consistiu de 20,0 mmol L-1 de tetraborato de sódio e 15,0 mmol L-1 de tampão Tris-ABen (pH 9,15 ± 0,03), tensão de +20 kV, injeção de 4 segundos a 50 mbar, 215 nm, utilizando levofloxacina como padrão interno. Uma amostra de preparado sólido para bebida de chá sabor limão, possuindo em sua constituição os quatro edulcorantes foi analisada, sendo o seu pré-tratamento constituído unicamente da filtração da mesma, após reconstituição, sem nenhuma derivatização. Apesar da metodologia analítica não ter sido validada, algumas figuras de mérito foram avaliados: linearidade, seletividade, limites de detecção e quantificação, precisão, recuperação e robustez. Os parâmetros avaliados demonstram um coeficiente de regressão maior que 0,98, além não apresentar falta de ajuste na faixa de concentração testada, avaliado com 95% de confiança, para todos os analitos. A seletividade foi testada mediante curva de adição de padrão, podendo-se observar um paralelismo entre os coeficientes angulares dos padrões e na amostra, indicando seletividade da metodologia. O RSD (%) para tempo de migração e área utilizando razão com padrão interno foi menor que 5% para a área e menor que 2% para o tempo de migração para os quatro analitos, considerando amostra e padrão. Os limites de detecção encontrados foram 6,8 mg L-1 para aspartame, 12 mg L-1 para ciclamato, 0,50 mg L-1 para sacarina e 3,3 mg L-1 para acesulfame-K, sendo valores mais significativos do que aqueles encontrados na literatura para determinação por CE e muito competitivos, senão melhores, que a determinação por outras técnicas. A exatidão mostrou-se dentro de limites aceitáveis, tendo os valores de recuperação no intervalo de 91,9 a 102,2%. / An innovative methodology was developed to simultaneously separate and quantify aspartame, cyclamate, saccharin and acesulfame-K through capillary electrophoresis with direct and indirect detection of UV, analysis time of roughly 6 minutes and with no sample derivatization. As the cyclamate has low absorptivity we used a system of electrolyte added to a chromophore, which allowed the indirect detection of this analyte. The wavelength was chosen taking into account an intermediary absorptivity among chromophore electrolyte, aspartame, saccharin and acesulfame-K. After testing some chromophores, the benzoic acid was selected as the most appropriate. A point to be considered is that food matrices have benzoic acid in its constitution, used as a preservative. Although it is still detected in the electrolyte system and the proposed analytical conditions, its quantification cannot be attained due to its inclusion in the electrolyte, showing signs of lack of adjustments of the linear model with 95% confidence. The ideal condition for electrophoretic separation was obtained by applying 32 factorial design. The optimization consisted of 20.0 mmol L-1 of sodium tetraborate and 15.0 mmol L-1 Tris-Aben (pH 9.15 ± 0.03), voltage of +20 kV, injection of 4 seconds at 50 mbar, 215 nm, using levofloxacin as internal standard. A sample of a solid prepared for drink lemon tea with the four sweeteners in its constitution was analyzed, and its pre-treatment consisting only of filtering the sample, after reconstitution, without any derivatization. Even though the analytical methodology was not validated, some important figures were evaluated: linearity, selectivity, limits of detection and quantification, precision, recovery and strength. The parameters assessed showed a regression coefficient greater than 0.98 and did not show lack of adjustment in the concentration range tested, evaluated as 95% granted for all analytes. Selectivity was tested through standard addition curve, which makes possible the observation of parallelism between the slopes of the patterns and the sample, indicating selectivity of the methodology. The RSD (%) for migration time and area using ratio as internal standard was less than 5% for the area and less than 2% for migration time for the four analytes, considering sample and standard. The detection limits found were 6.8 mg L-1 for aspartame, 12 mg L-1 for cyclamate, 0.50 mg L-1 for saccharin and 3.3 mg L-1 for acesulfame-K. These values are more significant than those found in the literature for determination by CE and they are very competitive, if not better, than the determination by other techniques. The accuracy was found to be within acceptable limits, and the recovery values in the range of 91.9 to 102.2%.

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.