In this study, we proposed a new drying process that uses microwave energy for evaporating moisture and a specific fluidization technique, the spouted bed, to improve uniformity in microwave heating. Experimental studies with two model foods were conducted to validate this process. In experiments with evaporated diced apples, particle circulation in the spouted bed provided uniform heating and resulted in improved quality. Temperature variation during drying was less than 4°C in diced apples (Malus domestica Borkh ). Less discoloration, lower bulk density, and higher rehydration compared to dried diced apples from conventional drying methods were observed. Blueberries (Vaccinium corymbosum L) dried with the combined microwave and spouted bed (MWSB) technique had a lower bulk density and more reddish and less blue color compared to blueberries dried with conventional methods. MWSB dried blueberries exhibited a higher rehydration ratio in shorter soaking times. Analysis of flavor volatiles identified three unique flavor compounds (2-Butanone, 2-methyl butanal, and 3-methyl butanal) in MWSB dried blueberries. A substantial reduction in drying time was achieved in both drying experiments.; A comprehensive model was developed to describe heat and mass transport in hygroscopic porous media. A special attention was given to internal vapor generation and bound water transport. Scaling technique was used to simplify the drying equations. The governing equations were solved using the Crank-Nicolson numerical technique. Experiments with diced apples were conducted to validate the model. The average moisture content, pressure increase, and inner temperature of diced apples were measured and good agreement with model predictions was achieved. The simulation demonstrated that for medium and low moisture porous media, surface moisture accumulation similar to that in high moisture, high intensity microwave drying was observed during the beginning of drying. The moisture profile in the diced apples suggested the importance of capillary flow in microwave drying. A temperature leveling effect was realized both numerically and experimentally.; All the parameters used in model were for product of our concern, diced apples. Three experiments were designed to measure effective diffusivity, permeabilities, and dielectric properties of apples. The temperature and moisture dependencies of these properties were also determined.
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