Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.5/3897
Título: Efeitos da substituição da sacarose por edulcorantes intensos e agentes de corpo nas caracteristicas físicas e sensoriais em chocolate
Autor: Bogalho, Joana Santos
Orientador: Almeida, Maria Helena Guimarães
Januário, Maria Isabel Nunes
Palavras-chave: chocolate
intense sweeteners
bulking agents
physical analysis
sensory analysis
low calories
Data de Defesa: 2011
Editora: ISA/UTL
Citação: Bogalho, Joana Santos - Efeitos da substituição da sacarose por edulcorantes intensos e agentes de corpo nas caracteristicas físicas e sensoriais em chocolate. Lisboa: ISA, 2011
Resumo: The prevalence of diseases such as diabetes mellitus and obesity has led to demand for alternative, low caloric foods traditionally high in sucrose and/or fat, such as chocolate. The aim of this work was to study the effects of the substitution of sucrose by the intense sweeteners rebaudioside-A and sucralose and its association with the bulking agents polydextrose, inulin and isomalt on physical and sensory properties of chocolate. Chocolate masses prepared in the laboratory were compared to physical and sensory. The physical examination consisted in studying the rheological behavior (through scans of tension, frequency, deformation velocity and temperature) and texture profile of the masses. The chocolates were subjected to descriptive sensory analysis by a panel of thirteen semi-trained tasters. These studies were preceded by a preliminary study of sensory characterization of commercial chocolates made with different types of sweeteners. From the results obtained in the rheological tests, it was concluded that the bulking agent leading to features closer to the chocolate made in the laboratory with sucrose (Standard) and / or its corresponding commercial, is isomalt because is to present an internal structure, elastic component (G ') and viscous (G'') similar to these chocolates, but also for having close values of viscosity in the range of deformation velocity tested (0.2 to 200 s-1) indicating that this agent body provides an internal structure similar to sucrose. In chocolates made with polydextrose, G' is always lower than G'', in other words, it is more fluid and have a more fragile structure. From the results of texture analysis, we conclude, however, that polydextrose is the agent bulking agent that leads to a texture profile closer to the standard chocolate. However, when compared with the commercial chocolate, isomalt is the one that has an internal structure more similar to it. Despite these observations, we found no significant differences in hardness values of all the chocolates made. The results of sensory analysis showed that isomalt chocolate gives greater sweetness and softens the bitterness, and that polydextrose does not affect the characteristics, like bitterness and astringency, transmitted by the other ingredients. The rebaudioside A has a higher sweetening power but causes feelings of bitterness, although it is strongly attenuated when used together with isomalt. The chocolates made with sucralose and isomalt were preferred by tasters because they are sweeter, but unlike the previous ones, showed clear differences with regard to chocolate made with sucrose. It was concluded that the association of the isomalt and rebaudioside-A is potentially interesting in terms of physical and sensory characteristics, as it could be an excellent solution to enjoy the high sweetness of a natural sweetener with no noticeable unpleasant sensory effects, justifying therefore, the continuation of this study in future.
Descrição: Mestrado em Engenharia Alimentar - Qualidade e Segurança Alimentar - Instituto Superior de Agronomia
URI: http://hdl.handle.net/10400.5/3897
Aparece nas colecções:BISA - Dissertações de Mestrado / Master Thesis

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