Effect of Ultra‐High‐Pressure Pre‐Treatment on the Physicochemical Properties of Radio Frequency Vacuum Dried Cistanche Slices

The utilization of pre-treatment has been a widely adopted method for enhancing the drying characteristics and overall quality of dried products. In this study, ultra-high-pressure pre-treatment technology was applied to examine the impact of varying ultra-high-pressure durations (10, 20, 30 min) and ultra-high-pressure powers (150, 250, 350 MPa) on the drying attributes, impregnation efficiency, quality, and microstructure of sliced Cistanche during radio frequency vacuum drying. The finding indicated that the ultra-high-pressure pre-treatment was conducive to shortening the drying time; increasing the drying rate of Cistanche; and effectively retained the content of echinacoside (3.09 ± 0.21 mg/g), Jinshi sericin (0.68 ± 0.05 mg/g), and verbascoside (5.56 ± 0.09 mg/g). The impregnation plots after treatment showed that the cell permeability of the Cistanche pre-treated with ultra-high-pressure was enhanced, and the value of the impregnation rate was increased (1.38-2.04). Compared with the untreated samples, the tissue of the treated Cistanche showed a loose and irregular structure due to the cellular rupture and loss of expansion pressure. These findings not only offer valuable theoretical insights for optimizing processing technology but also hold potential for facilitating the industrialization of sliced Cistanche in future studies.