Combined drying of shimp with voltage electric field and hot air

In order to improve the drying qualities of shrimp, a combined drying process of high voltage electric field and hot-air was studied. It was compared with single-stage high voltage electric field drying as well as single-stage hot-air drying on the basis of drying time, energy consumption, shrinkage rate, rehydration rate and sensory qualities. The results show that, with the high voltage electric field at 35kV combined with hot-air at 45℃, the drying time can be reduced by 50% compared with those by single-stage hot-air drying at 45℃. The drying rate is close to that of single-stage hot-air drying at 80℃, however, the energy consumption was 51.9% lower than single-stage hot-air drying at 80℃, and the dried shrimp has lower shrinkage rate and higher rehydration rate. When the voltage and temperature of hot air were controlled at 35 kV and 45℃, the rehydration rates after 10 minutes and 20 minutes of the shrimp dried by the combined drying process were 51.86% and 67.29%, which were 2.3% and 1.33% more than that of hot-air drying shrimp respectively. The shrinkage rates of the dried shrimp under the combined drying process was 47.8%, which was 5.5% less than that of hot-air drying shrimp. Furthermore, the dried shrimp under the combined drying process had better sensory qualities such as better color, better texture and lower distortion. Compared with hot-air drying the combined drying has advantages and can be used as a substitute method for traditional drying method.