Abstract

The effects of three different drying tecnologies (PVD, THC-HAD, and IR-HAD) on drying kinetics, microstructure, energy consumption, and quality, that is, rehydration ratio (RR), color parameters (L*, a*, b*), total color difference (△E), Panax Notoginseng saponins (PNS) content, and ginsenosides content (R₁, R_g1, R_e, R_d, R_b1) of Panax Notoginseng roots were examined experimentally. As expected, the drying time decreased with increase of drying temperature from 40 to 70 °C, and PVD needed the shortest drying time, followed by THC-HAD and IR-HAD. The drying time of PVD was reduced by 22.9% and 30.2% compared with THC-HAD and IR-HAD at 60 °C, respectively. PVD can effectively shorten the drying time, and the dried samples had better brightness (about 50.2 ± 1.3), rehydration ability (range from 1.6 to 2.1) through promoting the porous structure formation of dried roots. But PVD is not the most suitable drying technology in terms of ginsenosides content preservation and energy consumption, when compared to THC-HAD and IR-HAD. For Panax Notoginseng roots need to be used as medicine, IR-HAD is a promising drying technology, especially at 50 °C, as it allowed high retention of PNS (about 12.5%) and low unit energy consumption (about 19.5 kW·h/kg). Therefore, the current findings indicate that IR-HAD drying has the potential to produce high-quality dried Panax Notoginseng roots on commercial scale.

摘要

三种不同的干燥技术（PVD，THC-HAD和IR-HAD）对干燥动力学，微观结构，能耗和质量的影响，即水合比（RR），颜色参数（L *，a *，b *），总色差（△ ë），三七皂苷（PNS）的含量，和人参皂苷含量（R ₁，R _G1，R _ê，R _d，R _B1的）三七根进行了实验检查。正如预期的那样，随着干燥温度从40升高到70°C，干燥时间减少，PVD需要最短的干燥时间，其次是THC-HAD和IR-HAD。与60°C下的THC-HAD和IR-HAD相比，PVD的干燥时间分别减少了22.9％和30.2％。PVD可以有效地缩短干燥时间，并且通过促进干燥根的多孔结构形成，干燥后的样品具有更好的亮度（约50.2±1.3），补水能力（1.6至2.1）。但是就人参皂苷含量的保存和能量消耗而言，与THC-HAD和IR-HAD相比，PVD并不是最合适的干燥技术。对于三七根需要用作药物，IR-HAD是一种很有前途的干燥技术，尤其是在50°C的条件下，因为它具有较高的PNS保留率（约12.5％）和较低的单位能耗（约19.5 kW·h / kg）。因此，目前的发现表明，IR-HAD干燥具有在商业规模上生产高质量干燥三七根的潜力。