罗非鱼片的热风微波复合干燥特性

Study on Characteristics of Hot Air-Microwave Drying of Tilapia Fillets

研究了3mm厚的罗非鱼鱼片分别在40℃和50℃的热风温度条件下干燥4h后,又分别于200、400、600W的微波功率下干燥不同时间的干燥速率变化和热风微波干燥对鱼片品质的影响。结果表明,在热风初干温度和时间不变的条件下,当微波干燥时间一定时,罗非鱼片的含水率随微波功率的增大而降低;当微波功率一定时,罗非鱼片的含水率随微波干燥时间的延长呈现先快后慢的速率下降。在热风初干温度不同时,较高的热风温度有利于鱼片在微波干燥阶段的含水率的降低。罗非鱼片在热风微波后的收缩率和复水率随微波功率的升高而增加,当微波功率一定时,收缩率和复水率随热风初干温度升高而增加。而复原率则随微波功率的增加而降低,当微波功率一定时,热风初干温度如果越高,那么复原率越低。

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.