Abstract: The effects of main processing parameters(drying temperature,wind velocity and material density) on drying rate,unit energy consumption as well as the main nutrient components of cooked sweet potatoes during hot-air drying were studied,adopting central composite rotatable design and respond surface methodology. The correlative statistical mathematical models were established,and then the air-drying process parameters of cooked sweet potatoes were optimized. The optimal process parameters are as follows:drying temperature 73.89 ℃,wind velocity 4.91 m/s and material density 2.54 kg/m2. Under these drying conditions,the drying rate is 1046.333 g/min,and the unit energy consumption is 0.583 W/g. The contents of starch,reducing sugar,protein,fiber and VC in obtained sample are 50.435 %,29.428 %,6.288 %,6.271% and 2.509 mg/100 g respectively,and the comprehensive index is 5.026863.

Key words: cooked sweet potato, hot-air drying, parameter optimization, mathematical model