Drying and quality characteristics of tilapia fish fillets dried with hot air-microwave heating

The aim of this work was to study the effect of hot air-microwave heating on the drying and quality characteristics of fresh tilapia fish fillets. Experimental drying curves were obtained at three microwave powers (200, 400 and 600 W) after hot air drying at two air temperatures (40 and 50 °C) and a constant air velocity of 1.5 m/s. Some quality indicators such as shrinkage, rehydration and recovery properties were investigated. Results showed that an increase in microwave power resulted in a decrease in final moisture content when drying for the same period of time. The higher the hot air temperature, the higher the dehydration rate was. The shrinkage ratio and rehydration ratio increased as the microwave power and air temperature increased. However, the recovery ratio decreased as the microwave power and air temperature increased. Lower hot air temperature and microwave power are beneficial to keep the quality of tilapia fillets.

Research highlights▶ Hot air-microwave drying decreased remarkably dehydration time of tilapia fish fillets. ▶ An increase in microwave power resulted in a decrease in moisture content of fish fillets. ▶ The moisture difference was obvious in starting point for the microwave drying. ▶ The shrinkage and rehydration ratio increased with increase of hot air temperature. ▶ The shrinkage and rehydration ratio increased with increase of hot air temperature.