Abstract:The drying characteristics of Camellia oleifera seeds and the internal moisture diffusion coefficient at different drying temperatures were studied. According to the pre-test results, the drying characteristics of Camellia oleifera seeds were investigated at different air temperatures and different initial moisture contents. The empirical relationships between the natural logarithmic lnMR and drying time, moisture effective diffusion coefficient Deff and drying air temperature was established. The applicability of nine mathematical models in hot air drying of Camellia oleifera seeds was compared. The results showed that there was no apparent constant-rate drying period in the hot-air drying process, and moisture removal mainly occurred in the falling-rate drying period. The initial moisture content and hot-air temperature were the main factors that affected the drying process. The lower the initial moisture content was, the higher the drying temperature was, the shorter the drying time to the target moisture content was. In the process of drying, the effective moisture diffusion coefficient was increased with the increase of temperature. When the hot-air temperature was increased from 50℃ to 80℃, the coefficient was increased from 1.3132×10-9m2/s to 3.9223×10-9m2/s and the activation energy was 33.6193kJ/mol. The results of comparing the values of the correlation coefficient R2, the root mean square error eRMSE and the chi-square χ2 showed that the Lewis model was the optimal model for describing the hot-air drying of Camellia oleifera seeds and the predicted drying characteristic curve fitted well with experimental results obtained.