人参鲜药干制/复水过程水分状态与化学成分变化规律研究

Change of moisture transformation and chemical constituents in drying/rehydration process of fresh Chinese medicines(ginseng)

目的研究新鲜人参样品干制(干燥/蒸制)和复水(煎煮)过程中水分状态与含量变化以及有效成分含量变化规律,为优化中药干制/复水条件、科学判定过程终点提供技术支持,为探究中药鲜用/干用/制用差异提供新的科学视角。方法采用低场核磁共振与成像技术(LF-NMR/MRI)测定不同工艺条件下样品水分随时间的迁移变化规律;采用HPLC法测定不同样品中人参皂苷类主要成分的含量变化。结果水分与化学成分含量测定结果显示,蒸制180 min时鲜参炮制充分,此时水分饱和、人参皂苷类成分变化趋于稳定、总皂苷含量较高;鲜参和新蒸制红参在不同温度下干燥12.5 h时,40℃下均未干燥彻底,50℃下生晒参仍含有3.02%的水分、红参已达干燥终点,60℃下二者均达到干燥终点,且50℃下二者人参总皂苷含量均最高,综合结果表明50℃热风干燥工艺更优;复水(煎煮)过程中,60min饮片水分充分饱和且人参总皂苷含量较高,优于30 min和120 min,为较优煎煮条件;鲜参在蒸制/干燥/煎煮等过程中水分及人参总皂苷含量均低于鲜品,提示鲜用对保存和发挥中药初始药效物质基础状态具有重要意义。结论采用LF-NMR/MRI与HPLC技术,重点关注人参鲜品在干制(干制、炮制)与复水(煎煮)过程中的水分与化学成分含量变化,为中药干制/复水终点判定与工艺条件优化提供了新的技术手段,也为阐释与探究中药鲜用/干用/制用理论提供了新的科学依据。

Objective To study the changes rule of active ingredients content and moisture status during the process of dry (drying/steaming) and rehydration (decoction), which could provide technical support for optimizing the dry/rehydration conditions of Chinese medicine and scientifically determine the end point of the process, and it also provides a new scientific perspective for exploring the differences in fresh/dry/processing of traditional Chinese medicine. Methods Low-field NMR and imaging techniques (LF-NMR, MRI) were used to determine the change of water with time;The content changes of main composition of ginsenosides in different samples were determined by HPLC. Results The results of determination of moisture and chemical composition showed that: The fresh ginseng was steamed for 180 min. At this time, the water was saturated, the ginsenosides tended to be stable, and the content of total ginsenosides was high. When fresh ginseng and red ginseng were dried at different temperatures for 12.5 h, they were not completely dried at 40 ℃ hot-air drying;The sun-dried ginseng still contained 3.02% water at 50 ℃ hot-air drying, and the red ginseng has been dried;Both of them have been dried at 60 ℃, but the content of total ginsenosides in ginseng and red ginseng was the highest at 50 ℃. The comprehensive results showed that ginseng and red ginseng were better at 50 ℃ hot-air drying. During rehydration (decocting), the moisture content of the decoction for 60 min was fully saturated and the content of total ginsenosides was higher, better than 30 min and 120 min, which was a better decocting condition. The moisture content and total ginsenosides content of fresh ginseng were higher than those of steaming/drying/decocting ginseng, suggesting that fresh ginseng is great significance for preserving and exerting the basic state of the initial pharmacodynamics of traditional Chinese medicine. Conclusion In this study, ginseng was used as an example. LF-NMR/MRI and HPLC techniques were used to focus on the changes of moisture and chemical contents during the drying (drying, processing) and rehydration (decocting) of traditional Chinese medicines. It provides a new technical method for the determination of the dry/rehydration end point and the optimization of process conditions for traditional Chinese medicine, and also provides a new scientific basis for the interpretation and exploration of the theory of fresh/drying/processing of traditional Chinese medicine.