Coupling electrostatic and static magnetic fields during drying: A strategy to enhance drying characteristic, functional properties and microstructural modification fresh-cut purple yam.

This study investigated the effects of electric (EF), static magnetic fields (MF), and coupled electromagnetic (EMF) fields applied during the drying process on the quality attributes of yam slices. EF and MF treatments reduced drying time by 44.44% and 33.32%, respectively, compared to the control, and lowered relative crystallinity to 41.0% and 41.8%. EMF-assisted drying was most effective with 120 min drying time, significantly enhancing drying kinetics and water mobility, improving rehydration capacity, and resulting in the highest levels of color retention and bioactive compounds among all drying methods. FTIR spectroscopy and XRD analysis confirmed that all treatments maintained the A-type crystalline pattern while reducing crystallinity and short-range molecular order. EMF assisted drying also substantially reduced the gelatinization enthalpy and temperatures of yam starch. These improvements are attributed to field-induced microstructural modifications, including increased porosity and disruption of starch crystallinity. The findings confirm that in-process EMF assistance is a promising technology for producing high-quality dried yam products with enhanced efficiency and functionality.