Abstract: A three-factor quadratic regression rotation combination design was adopted to optimize the explosion puffing drying process of apple.The effects of apple slice thickness,vacuum drying temperature and time on water content,hardness,crispness and color of explosion-puffed product were analyzed in this study.Based on the experimental data,the quadratic regression model on the above four indexes was deduced,and then the above three variables were analyzed with interaction effects and response surface methodology(RSM).The optimal technical conditions are determined as follows:apple slice thickness 3 to 4 mm,vacuum drying temperature 83 to 89 ℃ and vacuum drying time 35 to 45 min.

Key words: apple, variable temperature and pressure difference, explosion puffing drying, technics, optimization