延胡索药材干燥动力学及其化学成分变化规律研究

Drying kinetics and chemical composition changes of Corydalis yanhusuo

目的建立延胡索Corydalis yanhusuo鲜品直接干燥、煮后及蒸后干燥的共有干燥模型,测定其干燥动力学参数,研究其有效成分在干燥过程中的变化规律。方法应用10种(Page、WangandSingh、Two-termexponential、Newton、Logarithmic、Aghbashlo、Two-term、Midilli、Diffusion approach、Weibull)薄层干燥模型对50、60、70、80℃条件下3种不同加工方式的延胡索药材的干燥曲线进行拟合,采用决定系数(R2)、卡方(χ^(2))及均方根误差(root mean squared error,RMSE)判断拟合方程的优劣;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变化规律。结果确定了3种不同加工方式的延胡索中药材干燥的共有模型(Midilli模型),3种不同加工方法的延胡索药材的有效扩散系数(effective diffusivity,Deff)值(7.09×10^(-9)~4.66×10^(-8)m^(2)/s)及活化能(activation energy,Ea)值(1.52~1.82k J/mol),多糖、黄连碱、延胡索乙素、紫堇碱、总生物碱(原阿片碱、海罂粟碱、黄连碱、延胡索乙素、巴马汀、小檗碱、去氢紫堇碱、紫堇碱等8种生物碱含量的和)的变化均符合零级动力学规律,这5种化学成分的含量随干燥时间的增加而减少。结论生品与煮品、蒸品的干燥效率在较低温度时存在较大差异,随着干燥温度的升高,这种差异逐渐缩小,蒸、煮在一定程度上有利于干燥;干燥过程对延胡索品质有较大影响;为延胡索药材干燥方法提供参考,对指导延胡索实际生产和提高其质量与品质具有重要意义。

Objective To establish a common drying model of fresh Yanhusuo(Corydalis yanhusuo)for direct drying,boiling and steaming drying,determine its drying kinetic parameters,and study the changes rule of its active ingredients during drying process.Methods Ten thin layer drying models(Page,Wang and Singh,Two-term exponential,Newton,Logarithmic,Aghbashlo,Two-term,Midilli,Diffusion approach,Weibull)were used to fit the drying curves of three kinds of C.yanhusuo at 50,60,70 and 80℃,and the determination coefficient(R2)and chi square(χ^(2))and root mean square error(RMSE)were used to judge the fit equation;The drying kinetic parameters were calculated according to Fick diffusion law;According to the principle of chemical kinetics,the change rule of effective components in the drying process was studied.Results The common drying model(Midilli model)of Chinese medicinal materials of C.yanhusuo by three processing methods was determined,and the effective diffusivity(Deff)of three Chinese medicinal materials of C.yanhusuo were in the range of 7.09×10^(-9)—4.66×10^(-8) m^(2)/s and activation energy(Ea)were in the range of 1.52—1.82 kJ/mol.The changes of polysaccharides,coptisine,tetrahydropalmatine,corydaline and total alkaloids(the sum of the contents of eight alkaloids,namely protopine,glaucine,coptisine,tetrahydropalmatine,palmatine,berberine,dehydrocorydaline,corydaline)all conformed to the first-order kinetic law,and the contents of these five chemical components decreased with the increase of drying time.Conclusion The drying efficiency of raw products,boiled products and steamed products has a great difference at a lower temperature.With the increase of drying temperature,the difference is gradually reduced,and steaming and boiling are beneficial to drying to a certain extent;The drying process has great influence on the quality of C.yanhusuo;This study provides a reference for the drying method of C.yanhusuo,and is of great significance for guiding the actual production of C.yanhusuo and improving its quality.