Alireza Yousefi; Shahla Khodabakhsh Aghdam; Mahdi Pourafhar Chenar; Mehrdad Niakosari
Abstract
In this study, mathematical modeling of hot air-drying of thin-layer papaya (Carica papaya L.) slices with 5±1 mm thickness pretreated in osmotic solution (50% sucrose) was investigated. Thin-layer drying was conducted under three different drying temperatures of 40, 50 and 60 °C at a constant ...
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In this study, mathematical modeling of hot air-drying of thin-layer papaya (Carica papaya L.) slices with 5±1 mm thickness pretreated in osmotic solution (50% sucrose) was investigated. Thin-layer drying was conducted under three different drying temperatures of 40, 50 and 60 °C at a constant air velocity of 0.9±0.1 m/s and absolute humidity of 0.6 ± 0.02 g of water/kg of dry air. It was found that the drying process occurred in falling rate period over the drying time. The osmosis dehydration characteristics obtained by solid gain (SG), water loss (WL) and weight reduction (WR) parameters that increased with increasing immersion time. The effective diffusivity for papaya slices was within the range of 2.13×10-9 to 4.84×10-9 m2/s over the temperature range. The activation energy was 38.63 kJ/mol indicated the effect of temperature on the diffusivity. Based on the statistical analysis using coefficient of determination (R²) and root mean square error (RMSE), it was concluded that the best model in terms of fitting performance for hot air-drying of papaya pretreated in osmosis solution in all temperature range was Midilli et al. model.
Shahla Khodabakhsh Aghdam; Mahdi Moradi; Alireza Yousefi
Abstract
In this research, Papaya slices with dimensions of 0.5×2×5 cm3 were dried at 45 °C using a cabinet dryer in which drying air velocity and relative humidity were 0.9 m/s and 30%, respectively. The moisture diffusion coefficient of Papaya was determined in this drying condition. Mass transfer equation ...
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In this research, Papaya slices with dimensions of 0.5×2×5 cm3 were dried at 45 °C using a cabinet dryer in which drying air velocity and relative humidity were 0.9 m/s and 30%, respectively. The moisture diffusion coefficient of Papaya was determined in this drying condition. Mass transfer equation with its boundary conditions was solved based on finite difference method. Finally, coefficient of determination and goodness of fitting between the gained theoretical model by solving mass transfer equation, and experimental data were obtained R2=0.996 and RMSE=0.00115. Therefore, finite difference numerical method showed a suitable correlation with low error into the experimental data for solving of mass transfer equation.
