[关键词]
[摘要]
目的 建立鸡矢藤、忍冬藤、首乌藤、番薯藤4种藤类中药材干燥共有模型,测定其干燥动力学参数,研究其有效成分干燥过程的稳定性。方法 应用9种薄层干燥模型(Page、Wang and Singh、Two-term exponential、Newton、Logarithmic、Aghbashlo、Two-term、Midilli、Diffusion approach)对40、50、60、70℃条件下4种藤类药材的干燥曲线进行拟合,采用决定系数(R2)、卡方(χ2)及均方根误差(RMSE)判断拟合的优劣;根据Fick扩散定律求算干燥动力学参数;根据化学动力学原理研究有效成分在干燥过程中的稳定性。结果 Aghbashlo模型可被选作描述4种藤类中药材干燥过程的最佳共有模型。4种藤类中药材的有效水分扩散系数(D)及干燥活化能(Ea)分别为1×10-10~1×10-9 m2/s及40~50 kJ/mol。熊果酸、二苯乙烯苷及多糖的降解均符合一级动力学规律。绿原酸的含量随干燥温度、干燥时间的增加而增加。结论 不同部位中药材的干燥动力学参数值可能具有不同的特征区间,其干燥过程可用特定的共有模型描述;干燥过程对中药材品质有较大影响。
[Key word]
[Abstract]
Objective To establish the common model of four kinds of rattan traditional Chinese medicinal materials (TCMM) (Paederiae Scandens Caulis, Lonicerae Japonicae Caulis, Polygoni Multiflori Caulis, and Ipomoea batatas Caulis) determinate the drying kinetic parameters, and study the stability of active ingredients in the drying process. Methods The experimental data of four rattan TCMM were fitted to the nine thin layer models (Page, Wang and Singh, Two-term exponential, Newton, Logarithmic, Aghbashlo, Two-term, Midilli, Diffusion approach) at the temperature of 40, 50, 60, and 70℃. R2, χ2, and RMSE were used as the criterion of fit. Fick diffusion law was used to calculate the drying dynamical parameters. Based on the principle of chemical kinetics, the stability of active ingredients in the drying process was studied. Results Aghbashlo model was the best one to describe drying process of four rattan TCMM. The effective moisture diffusion coefficients D and activation energy Ea of four rattan TCMM were between 1×10−10 and 1×10−9 m2/s and 40-50 kJ/mol respectively. The degradation reactions of ursolic acid, THSG, and polysaccharide conformed to the first-order kinetic equation. The content of chlorogenic acid increased with the drying temperature and drying time increased. Conclusion The drying dynamical parameters values of TCMM with different parts have different ranges, their drying process should be described by a common model. The quality of TCMM was affected greatly by drying process.
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[基金项目]
贵州省教育厅自然科学研究项目:贵州几种大宗藤类药材干燥特性及干燥品质变化规律研究[黔教科KY字(2015)369号];贵州省科技计划课题:黄精、何首乌蒸制关键技术研究与产业化应用[黔科合重大专项字[2015]6009-5];贵州省工程技术研究中心建设项目(贵州省药食同源植物资源开发工程技术研究中心)[黔科合G字(2015)4001号];贵州省中药材、民族药材质量标准研究课题(DB52/YC263-201)