Abstract:Microwave-thermal air coupling was employed to improve the processing efficiency and cooking effect of frozen French fries. The effects of microwave power，hot air temperature，and hot air motor speed on the cooking effect of French fries were investigated.Furthermore，the effects of microwave processing on the microstructure and harmful substance content of French fries were studied. The processing logic of hot air treatment followed by microwave treatment was determined by examining the dehydration rate of French fries after processing and the sensory score after cooking.With the sensory score of French fries as the evaluation indicator，the response surface methodology was employed to optimize the processing process. The optimized processing process of frozen French fries was as follows：hot air treatment at 225 ℃and 2 070 r/min for 14 min，followed by microwave treatment at 1 250 W for 6 min. Under these conditions，the sensory score of French fries after cooking was 25.7 points，which was close to the experimental value，with the error less than 5%，indicating that the regression model had a good guiding effect on the processing of French fries. After microwave-thermal air coupled processing，the surface of French fries presented a porous microstructure，which made the taste of French fries crisper and reduced the content of acrylamide.