Abstract

In order to explore the feasibility to enhance drying kinetics, the effects of pulsed vacuum drying (PVD) under different temperatures (55, 60, 65, 70, and 75 °C) and pulsed vacuum ratio (PVR) (3:16, 6:16, 9:16, 12:16, 9:10, 9:13, and 9:19 min/min) on the drying kinetics, energy consumption, and quality attributes of Panax notoginseng roots in terms of color parameters (L*, a*, b*, and △E), the contents of ginsenosides (R₁, R_g1, R_e, R_d, R_b1), and Panax notoginseng Saponins (PNS) are evaluated. The results were compared with those obtained under hot air drying (HAD) conducted at the temperature of 60 °C, relative humidity of 12%, and air flow rate of 0.3 m/s. PVD at 75 °C and PVR of 9:16 min/min resulted in the shortest drying time, i.e., 26.6 h, while PVD at the temperature of 65 °C and PVR of 9:13 resulted in the highest PNS content, i.e., 9.03%. Among different drying conditions, the temperature of 65 °C and PVR of 9:16 min/min are recommended as the most suitable ones for drying of whole Panax notoginseng roots in terms of drying time, energy consumption and quality of final product.

摘要

为了探索提高干燥动力学的可行性，脉冲真空干燥 (PVD) 在不同温度 (55、60、65、70 和 75 °C) 和脉冲真空比 (PVR) (3:16, 6 ：16，九点16，12时16分，9点10分，9点13分，和9时19分钟/上干燥动力学分钟），能量消耗，以及质量属性三七中的色彩参数来根（L * 、a*、b*、△E）、人参皂苷（R ₁、R _g1、R _e、R _d、R _b1）、三七的含量评估皂苷（PNS）。将结果与在 60 °C 的温度、12% 的相对湿度和 0.3 m/s 的空气流速下进行的热风干燥 (HAD) 下获得的结果进行比较。PVD 在 75 °C 和 PVR 为 9:16 min/min 的干燥时间最短，即 26.6 h，而 PVD ​​在 65 °C 的温度和 PVR 为 9:13 导致 PNS 含量最高，即， 9.03%。在不同的干燥条件中，从干燥时间、能耗和最终产品的质量来看，65°C 的温度和 9:16 分钟/分钟的 PVR 被推荐为最适合三七全根干燥的条件。