Effect of different drying methods on ginsenosides in flower of Panax ginseng and Panax quinquefolius / 中草药

ABSTRACT

Objective: To select the reasonable post-processing methods after harvest of the flower of Panax ginseng (FPG) and Panax quinquefolius (FPQ). The present study evaluated the effect of different drying methods on the quality of FPG and FPQ based on the contents of 14 ginsenosides. Methods: The contents of 14 ginsenosides were quantified by HPLC including ginsenosides Rg1, Re, Rb1, Rc, Rb2, Rb3, Rd and their corresponding malonyl-ginsenosides (m-Rg1, m-Re, m-Rb1, m-Rc, m-Rb2, m-Rb3, and m-Rd). Results: The contents of 14 ginsenosides were highest by oven drying at 40℃, followed by freeze drying, microwave drying, and infrared drying, and decreased with the increased temperature. The contents of malonyl-ginsenosides obviously decreased with reaching a high temperature (> 100℃). The decrement of malonyl-ginsenosides and the variation of corresponding ginsenosides was not equivalent, and the total content of 14 ginsenosides was also reduced. Conclusion: Oven drying at 40℃ is a suitable drying method for keeping the content of original ginsenosides, and oven drying at high temperature (> 100℃) can prompt the transformation into rare ginsenosides. Different drying methods can be selected according to different purposes in clinical application.