Abstract: The characteristics of hot air-microwave drying of fresh tilapia fillets with the thickness of 3 mm during drying at different microwave powers (200 W to 600 W) and different hot air temperatures (40 ℃ to 50 ℃) were investigated. At the same time, the effects of hot air-microwave drying conditions on quality of dried tilapia fillets were also investigated in this study. Results showed that the increase of microwave power results in the decrease of moisture content of tilapia fillets when other factors including hot air drying temperature and time are hold. The higher the hot air temperature is, the faster the hot air-microwave drying rate of tilapia fillets is. The shrinkage and rehydration rate of dried tilapia fillets by hot air-microwave drying increase as microwave power or air temperature rising. However, the change of the recovery rate is contrary to those of the shrinkage and rehydration rate. Therefore, low hot air temperature and microwave power are beneficial to keep the quality of dried tilapia fillets.

Key words: tilapia fillets, hot air-microwave drying, characteristics