Influence of ultrasonic pretreatment on electrohydrodynamic drying process of goji berry
Jiabao Ni, Changjiang Ding, Yaming Zhang, Zhiqing Song, Wenqian Xu
Abstract
In order to comprehensively investigate the effect of ultrasonic pretreatment on electrohydrodynamic (EHD) drying process of goji berry, the drying experiments of goji berry by ultrasonic pretreatment combined with EHD drying were studied in this paper. The results showed that the drying speed of goji berry after ultrasonic pretreatment was significantly higher than that of the control. Among them, the best effect was achieved when ultrasonic power was 200 W, the treatment time was 20 min, and the treatment temperature was 35°C. Ultrasonic pretreatment has a great influence on the drying rate, effective moisture diffusion coefficient, and rehydration rate, and has little effect on the shrinkage rate. By means of scanning electron microscope and infrared spectrum, it was found that the microstructure of goji berry was significantly changed by ultrasonic pretreatment and the structural change has a great positive effect on improving the goji drying speed and preserving the effective ingredients. Practical applications In this paper, the optimal process condition of ultrasonic pretreatment on electrohydrodynamic (EHD) drying process of goji berry was crystallization, which provided a reference for the design and optimization of ultrasonic pretreatment on the EHD drying process. At the same time, the rehydration rate and drying rate of goji berry were improved by ultrasonic pretreatment, which is of great significance for further research on ultrasonic pretreatment on the EHD drying process of goji berry.