Study On Model Of Equilibrium Moisture Content And Hot Air Drying And Optimum Technology Of Eggplant

The hot air drying is widely used in agricultural materials but it still lacks a complete basic research for eggplant. So the paper used theoretical and experimental methods to study on hot air drying of eggplant.By the experiments on equilibrium moisture content of the eggplant slices, the equilibrium moisture content values which were used to gain the desorption and absorption isotherm diagrams and establish simplified mathematical of equilibrium moisture content under 25℃ and 35℃ that they were combined to acquire the safety storage condition were obtained in different airtight temperature and relative humidity values according to the test data. Using the drying characteristic test to analyze the influence on drying rate and moisture content of the eggplant slices in different air temperature、wind speed、slice thickness and permeability temperature, as a result, the factor of the fastest drying rate and arriving 13% for the moisture content at the least time was 75℃、2.1m/s、4mm and 70℃ for air temperature、wind speed、slice thickness and permeability temperature respectively. The most suitable mathematical model was Midilli model during the eggplant drying by the MATLAB simulation for the relationship between moisture ratio and drying time. In the orthogonal experiment, the evaluative indexes such as color difference、sensory evaluation、moisture ratio after the eggplant drying and drying rate were used to make optimization research of drying technology. The result was that the optimal parameters were 65℃,2.1 m/s、4mm and 70℃ for air temperature、 wind speed、 slice thickness and permeability temperature respectively.