Modeling and mass transfer performance of Dioscorea alata L. slices drying in convection air dryer.

The drying experiments of Dioscorea alata L. slices were implemented in order to study the thin‐layer drying characteristics and kinetic in hot air forced convection tunnel dryer. The influences of temperatures, velocity, and slice thickness on the drying behavior were researched. Six commonly thin‐layer drying models were used to fit the experimental data to express the mass transfer characteristics. The fitting degree between models and experiment data was analyzed. The effective diffusion coefficients (Deff) and activation energy (Ea) were estimated. The air temperature, air velocity, and sample slice thickness had significant influence on drying time, dehydration rate, and Deff. The drying process had a momentary accelerating rate stage and a long falling rate stage; the Logarithmic model had good degree of fitting with all experiments data; and Arrhenius equation could be well expressed the relationship of Deff and drying temperature. The drying process of hot air thin layer of Dioscorea alata L. can be better described by the Logarithmic model. At the range of research conditions, the Deff value ranged from 4.77 × 10−10 m2/s to 8.90 × 10−10 m2/s; the Ea value was 20.74 kJ/mol. Practical Applications: Postharvest processing and storage of agricultural products is very important, and drying is a traditional and practical technology. The common drying method is heat drying. This research discussed the thin‐layer drying of Dioscorea alata L. with hot air and obtained the appropriate drying conditions, applicable drying model, and relevant parameters, which could provide reference to select the drying conditions and design the drying equipment for practical application. [ABSTRACT FROM AUTHOR]