江西地产芳香性中药材干燥“保油-脱水-节耗”多维评价及工艺调控规律研究

The origin of fragrant medicinal herbs is crucial to the quality of medicinal herbs. The mechanism is unknown and the technology is unreasonable, resulting in a decrease in quality and low efficiency. "Chinese medicine quality should grasp from the source". How to achieve " Oil-retaining-Dewatering - Energy saving" by the study of the drying characteristics and regulation? There is no systematic study yet. In the previous research, based on the properties of porous media and the theory of heat and mass transfer, the research team fitted the data of moisture content, dehydration rate and drying temperature of peppermint, and found that the “Midilli model” can describe and predict the drying process accurately and dryly before and after drying Volatile oil and active ingredient content were significantly different. In this project, seven kinds of medicinal materials from Jiangxi origin were selected to characterize the physical parameters. The moisture content under different drying conditions was determined with the drying time. The existing dry model was fitted and corrected and the best model was screened. The quality evaluation model of "Trinity" will be established. The comparative study of quality changes of herbs will carried out at different temperatures, wind speeds and vacuum degrees over time. The quality degradation mechanism will be proven, and the quality degradation kinetics model will be established. The model was validated by pharmacodynamics evaluation. The optimum drying process was obtained under the multi-objective conditions such as water content, volatile oil content and quality. New ideas such as drying under reduced pressure and intermittent drying were proposed to clarify the scientific basis and to improve the dry quality and efficiency during drying process of aromatherapy Chinese medicine from both theory and practice.

芳香性药材的产地干燥对药材质量至关重要，干燥机理不明，工艺不合理，造成品质差效率低。“中药质量要从源头抓”。如何透过干燥特性和规律研究，达到“保油脱水节耗”的目的？尚无系统性研究。课题组在前期研究中，基于药材多孔介质属性和传热传质理论，拟合薄荷含水率、脱水速率与干燥温度的数据关系，发现Midilli模型较准确描述与预测其干燥过程，干燥前后挥发油及有效成分含量有显著差异。本项目选用6种江西地产药材，表征物性参数，测定随干燥时间在不同干燥工艺下的含水率，对现有干燥模型进行拟合修正，筛选最佳模型；建立“三位一体”的质量评价模式，对比研究药材在不同温度、风速、真空度下随时间的质量变化，探明质量退化机理，建立质量退化动力学模型；对干燥模型和质量退化模型联立求解，获得含水率、品质与效率多目标下的最佳干燥工艺，提出减压干燥，缓苏干燥新思路，阐明科学依据，从理论和实践二个层面提高芳香性药材干燥品质和效率

本项目基于芳香性中药干燥基础性研究，针对不同部位、质地和性状8种模型药材，分别进行干燥特性及数学模型拟合，模拟计算在不同热风温度、压力、风速风量等工艺参数下的干燥过程，探究其干燥前后挥发性成分和有效成分变化，获得干燥效率和干燥品质等多目标下的最佳干燥工艺，并形成共性技术，有的放矢和有据可循的优化芳香性中药的干燥方法和工艺。基本完成了计划研究内容，发表研究论文9篇，授权中药加工和干燥设备专利7项，达到了预期目标。.主要研究内容和结果如下： .1、通过对江香薷、薄荷、重瓣玫瑰、吴茱萸、江枳壳、紫苏、白术和香附8种芳香性中药干燥特性和干燥过程模拟展开研究，采用Midilli模型、Page模型等7种数学模型进行拟合，通过比较统计学参数：R2，χ2，RMSE以评价拟合度，结果表明：Midilli模型均最准确地描述与量化其干燥过程，阐明选择最佳工艺参数进行“保油—脱水—节耗”干燥的科学依据；对不同干燥条件下的实际含水率值和预测值进行了比较，结果表明，所得拟合结果与试验值吻合较好；测定了模型药材的水分有效扩散系数Deff和活化能Ea，探讨其作为判断干燥难易和质量退化关键性指标的科学性和可行性。.2、采用UPLC-Q-TOF-MS 和GC-MS等对干燥前后模型药材主要化学成分及挥发性成分进行了鉴定和含量测定，建立“化学”指标；通过E-nose和E-tongue评估香气和风味特征，建立“风味”指标；通过SEM建立“形性”指标；通过对抗氧化、抗菌等生物活性研究，建立“生物效应”指标。建立“四位一体”的综合评价模式，研究了12种芳香性中药干燥前后的品质变化，结果表明，干燥过程均不同程度的改变了模型药材的形态、香气和风味特征以及有效成分含量和生物活性，质量退化机理多以氧化、水解和酶促反应为主。.基于已上研究成果，项目组设计了符合中药干燥特性的五种干燥设备，具有可操作性高，量化控制，干燥速率快，药材品质好的特点，从理论和实践二个层面解决芳香性中药材干燥过程中质量退化和干燥效率低的问题，具有重要的理论价值和现实意义。