The effect of ultrasound pretreatment at different powers and temperatures on the drying process of cornelian cherry

In this research, the effect of ultrasound treatment at different powers and temperatures on the drying process of cornelian cherry by infrared dryer was investigated and modeled. The effect of the applied power by the ultrasonic device at three levels of 0, 75 and 150 W and the effect of the ultrasonic treatment temperature at three levels of 20, 40 and 60 °C on the mass transfer rate and the effective moisture diffusivity coefficient during the drying process of cornelian cherry were investigated. The results of this research showed that ultrasonic pretreatment before drying cornelian cherry by the infrared dryer, by creating microscopic channels on the product surface due to the cavitation phenomenon, makes it easier for moisture to exit from the product and thus reduces the drying time. By increasing the ultrasonic power from 0 to 150 W, the average drying time of cornelian cherry decreased from 73.2 minutes to 51.4 minutes. By increasing the treatment temperature from 20 to 60 °C, the average drying time of cornelian cherry decreased from 69.7 minutes to 55.7 minutes. The effect of power and time of ultrasound treatment on the effective moisture diffusivity coefficient changes of cornelian cherry was investigated and the results showed that with the increase in the power and temperature of the ultrasonic device, the values of this coefficient increase. By increasing the sonication power from 0 to 150 W, it was observed that the effective moisture diffusivity coefficient increased from 6.63×10-9 m2s-1 to 10.11×10-9 m2s-1. The average effective moisture diffusivity coefficient of cornelian cherry treated at temperatures of 20, 40 and 60 °C were 7.26×10-9 m2s-1, 8.10×10-9 m2s-1, and 9.45×10-9 m2s-1, respectively. In order to investigate the drying kinetics of cornelian cherry, mathematical models were fitted to the experimental data.