In order to investigate the temperature and moisture distribution in sweet potato slices during hot air drying,a numerical model was established to simulate the heat and mass transfer processes at different constant drying temperatures(50,60,70,80 ℃).Due to the significant shrinkage effect of the materials during hot air drying,the effective moisture diffusion coefficient changed,which affected the accuracy of simulation.Therefore,this study compared the heat and mass transfer processes,accounting for both temperature and shrinkage-related diffusion coefficients.The results showed that the shrinkage-related effective moisture diffusion coefficient can describe the hot air drying process of sweet potato chips more accurately.The coefficient of determination(R2)between the simulated value and the experimental value,based on the shrinkage moisture ratio and temperature,ranged from 0.976 to 0.994 and 0.961 to 0.981,respectively.To determine the influence of different hot air temperatures on the quality of dried sweet potato slices,the optimal tempera-ture for hot air drying of sweet potato slices was 60 ℃ based on the analysis of color difference,rehydration rate and sensory score.From the simulation test results,it concluded that the effective moisture diffusion coefficient increases with the increase of hot air temperature,and the heat and mass transfer coefficients were significantly affected by the change of sweet potato chip temperature and drying process.The developed model can serve as a reference for simulating the drying process of other agricultural crops under various drying temperatures.
关键词
甘薯片/热风干燥/数值模拟/传热、传质
Key words
sweet potato slices/hot air drying/numerical simulation/heat and mass transfer
维普
万方数据