Comprehensive analysis of ultrasound-assisted electrohydrodynamic technology on drying characteristics, quality attributes, and volatile profiles of yam (Dioscorea opposita)

Abstract

In this study, the systematic investigation focused on how varying power levels of ultrasonic (US) pretreatment, when integrated with electrohydrodynamic (EHD) drying, influence the physicochemical properties of yam. Yam samples were subjected to ultrasonic pretreatment at 30 °C for 30 min using power levels of 0 W (Control), 150 W, 180 W, 210 W, 240 W, and 270 W, respectively, followed by drying in an EHD system. During the drying process, a range of metrics were measured, including moisture content, average drying rate, color change, as well as rehydration capacity. Additionally, microstructure was analyzed using infrared spectroscopy while volatile component analysis was conducted. The findings indicated that the amalgamation of ultrasonic pretreatment with EHD drying exhibited statistically significant variations in efficacy across a range of ultrasonic power levels, accompanied by discernible distinctions in comparison to the control group. At 210 W, the sample demonstrated not only a minimal moisture content and the most rapid average drying rate, but also a considerable augmentation in both the effective water diffusion coefficient (1.35-fold in comparison with the control) and the rehydration rate (1.43-fold in comparison with the control), accompanied by statistically significant color differences. This research has revealed for the first time through data analysis on drying characteristics, quality parameters, and volatile components intrinsic quality changes in yam while laying a foundation for food-medicine dual-use materials represented by yam.