Yacon is a plant cultivated originally in South America for its tuberous, mildly sweet roots. Its low amounts of sucrose and glucose and high amount of non-digestible carbohydrates makes the yacon a good option for low- carbohydrate diets. However, shelf-life of yacon is limited to about seven days at ambient temperature, due to its high water content. Convective drying of yacon roots might extend their shelf-life without major inconvenient. This project aims to study the convective drying of slices of yacon using a numerical model. The methodology includes characterization of the product along the process, identification of kinetic parameters relevant to its structural changes, implementation of a physics-based model for such changes, and analysis of selected operating conditions, looking for process optimization. A convective dryer will be used. Two datasets will be constituted: for the slice placed at the center of the upper tray, shrinking and structural changes will be monitored along the process with the help of a Leica S6D microscope; for the remaining slices, mass will be measured along the process, and some will have their height measured with a micrometer. Both datasets will be obtained for a number of runs, under selected operating conditions. Modeling of heat and mass transfer for the slice at the center of the upper tray will consider i) kinetic parameters identified from real-time monitoring and ii) thermo-physical properties of the product from laboratory work. The reliability of model predictions will be assessed from comparisons with independent data at the same position. The role played by convection and thermal radiation throughout the convective dryer will be discussed from comparisons with data acquired for slices dried at other positions.
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