中药材变温/压干燥机制与品质调控规律研究

Traditional Chinese medicinal materials are raw materials for the preparation of Chinese herbal slices, and then directly formulated or prepared. Their quality directly affects the clinical efficacy of traditional Chinese medicine. Drying is one of the key process in the processing of traditional Chinese medicinal materials, it has a great impact on the quality of traditional Chinese medicinal materials Through the investigation actual production, traditional hot air drying method is still the main drying method at present, the backward drying technology often resulted in poor quality of products. Most of the existing technological studies paid attention to the back-end processes from extraction to preparation, while the front-end process of drying are not taken seriously enough: The imperfect quality evaluation system can not guarantee the quality of traditional Chinese medicinal materials; The lack of drying theory research leads to failure of theoretical guidance in the selection of drying process for traditional Chinese medicinal materials. In order to improve the drying technology and ensure the quality of medicinal materials. This subject intends to study the new drying technology of PVD, VTD and PSDFD, and a multi-dimensional quality evaluation system around "appearance - texture - composition - efficacy - use" has been established to ensure the quality of dried traditional Chinese medicinal materials; The LF-NMR, IRT etc. actual measurements was proposed to explain drying mechanism, in hope of developing the drying theory of traditional Chinese medicinal materials, providing theoretical support for the selection of drying process, and offering new ideas for the study of drying mechanism of other porous media.

中药材是制备中药饮片，进而直接配方或制剂的原料药，其品质直接影响着中药的临床疗效。干燥是中药材产地加工工序中的关键环节，对中药材的品质有很大影响。实际生产调研发现，目前中药材干燥方式仍以烘干法为主，干燥技术落后，药材品质不佳。而已有的工艺研究多关注后端中药提取到制剂环节，对前端中药材干燥工艺不够重视，尚缺乏干燥理论研究，药材干燥工艺的选择缺乏理论指导；质量评价体系不完善，无法保证药材品质。为提高干燥技术水平、保证药材品质，本课题拟对 PVD、VTD、PSDFD 新型变温/压干燥技术进行研究，围绕“外观-质构-成分-效-用”多维度建立干燥工艺的质量评价体系，为保证药材质量提供了保障；采用 LF-NMR、IRT 等实测分析阐释干燥机制，以期发展中药材干燥理论，为干燥工艺的选择提供理论支撑，并为其他多孔介质干燥机制研究提供新思路。

中药材是制备中药饮片的原料，其品质直接影响着中药的临床疗效。干燥是中药材产地加工工序中的关键环节，对中药材的品质有很大影响。实际生产调研发现，目前中药材干燥方式仍以烘干法为主，干燥技术落后，药材品质不佳。本课题对脉动压差干燥、变温干燥、闪蒸干燥新型变温/压干燥技术进行研究，研究主要内容包括：（1）干燥前杀青技术研究；（2）不同干燥技术对药材质量理化指标、干燥效率、药材活性的影响研究；（3）变温/压干燥技术的热质传递特征研究；（4）干燥过程中的对工艺敏感的有效成分变化规律研究；（5）组合干燥方式用于调控药材干燥过程与质量的研究。研究结果表明：（1）红外辅助蒸汽漂烫（ISB）显著缩短了处理时间、提高了PPO与POD的酶钝化效率，同时提高了酚类和黄酮的保有率、有利于保护色泽、减小皱缩；（2）热风干燥采用逐渐升温工艺可减小皱缩、提高有效成分保有率，脉动压差干燥、闪蒸干燥较热风干燥、真空干燥可显著提高干燥效率、缩短了干燥时间，较好的保留了有效成分和活性、有助于减小药材皱缩，但对于质地轻薄的金银花、菊花优势不明显；（3）干燥过程中自由水含量不断下降，一部分半结合水转变为结合水，干燥方式对水分状态的影响不明显；脉动压差干燥降低药材的干燥活化能，这是其提高干燥效率的机制之一；脉动压差干燥有助于提高药材干燥均匀性，这将有利于提高药材质量的均一性；（4）干燥过程中药材中的化学成分含量呈波动变化，提示化学成分变化机制可能涉及多个途径，如采后干燥初期在干燥条件胁迫下的次级代谢产物累积、化学成分状态与药材组织细胞结构的变化、高温与氧气等因素导致的成分破坏与转化；（5）组合干燥方式可发挥协同作用，克服单一干燥方式的缺陷，起到提高干燥效率、保护药材质量的作用。研究成果将为变温/压干燥技术应用于中药材产地加工提供数据与理论支撑。