Abstract:The objective was to investigate the effects of puffing initial moisture content and vacuum drying temperatures on the characteristics of apple slices dried by explosion puffing drying at variable temperatures and pressure difference. The drying kinetics model of explosion puffing drying at variable drying conditions was obtained. Results showed that the drying process of explosion puffing drying at variable temperatures and pressure difference obviously existed increase-rate, constant-rate and falling-rate period. Page model provided better simulation of drying curves for apple slices at different puffing drying conditions. The effective moisture diffusivity of apple slices dried by explosion puffing drying at variable temperatures and pressure difference was among 1.52×10-9~8.87×10-9m2/s. The established model can predict the moisture content change during explosion puffing drying time. Fitting undetermined coefficients k and n of Page model were linear with puffing initial moisture content and vacuum drying temperature. The coefficients of correlation r2 were 0.845 and 0.997, respectively.