Impact of different pretreatment methods on drying characteristics and microstructure of goji berry under electrohydrodynamic (EHD) drying process

The aim is to find better pretreatment method to improve the drying speed of goji berry under electrohydrodynamic (EHD) drying process. The drying characteristics and microstructure of goji berry using different pretreatment methods under EHD drying process were investigated. The results showed that the drying rate after pretreatment was significantly higher than those of non-pretreated goji berry, and the different pretreatment methods had different effects on the drying characteristics of goji berry in an EHD drying system. The effects of different pretreatment methods on effective moisture diffusion coefficient were listed in descending order as follows: KOH > NaOH > Na2CO3 > ultrasonic > sucrose ester. The pretreatment has a great influence on the rehydration rate, specific energy consumption and microstructure of goji berry dried by EHD. Two index sequence analysis of infrared spectroscopy during goji berries drying process were established. The difference among five pretreatment methods was analyzed.