Electrohydrodynamic Drying of Sweet Potatoes: Drying Characteristics, Mathematical Models, and Volatile Components

A comparative analysis was performed to evaluate the effects of electrohydrodynamic (EHD) drying versus hot air drying (HAD) and air drying (AD) on sweet potatoes. The results revealed that while EHD did not surpass HAD in drying rate, it demonstrated significant advantages in product quality. Compared to HAD, EHD-dried samples exhibit superior rehydration properties (improved by 0.78%-11.9%) and markedly better color retention, achieving the smallest total color difference (ΔE = 8.61) under 26 kV conditions. A total of 53 volatile compounds were identified, including aldehydes, ketones, and hydrocarbons. Among these, HAD samples exhibited the lowest diversity and content of volatile compounds. Volatile component analysis indicated that the EHD drying method was most effective in preserving sweet potato flavor compounds. The logarithmic model best fits the drying processes of sweet potatoes. Protein analysis showed the changes in α-helix and β-sheet. These findings indicate that EHD is not merely a faster drying method, but rather a low-temperature technology with broad prospects for producing higher-quality sweet potato dry products. This study elucidates key property changes induced by EHD and provides a theoretical foundation for its application in tuber processing.