前胡切片微波真空干燥特性分析及模拟

Drying Characteristics Analysis and Simulation of Peucedani Radix Slices during Microwave Vacuum Drying

关键词:  前胡切片  微波真空干燥  干燥特性  模拟  Weibull函数  香豆素

Key words:  Peucedani Radix slices  microwave vacuum drying  drying characteristics  modeling  Weibull function  coumarin

摘要:

目的 为了探索前胡切片在微波真空干燥过程的水分及其成分变化规律，以期有效提高前胡切片的干燥效率和饮片品质，开展了前胡切片微波真空干燥特性分析与模拟研究。方法 进行不同干燥条件（微波功率密度、真空度和切片厚度）的前胡切片微波真空干燥实验，研究干燥过程的水分比和干燥速率变化情况，运用HPLC法测定干燥后的前胡切片3个香豆素类成分（白花前胡甲素、白花前胡乙素和白花前胡素E）含量，并采用Weibull函数对干燥过程的水分比曲线进行模拟与分析。结果 前胡切片微波真空干燥过程存在加速、恒速和减速三个阶段。与真空度和切片厚度相比，通过提高微波功率密度可以更有效地缩短干燥时间、提高干燥效率。在实验参数范围内，较优干燥条件组合为：微波功率密度为3.0 W/g，真空度为800 Pa，切片厚度为2 mm。所有干燥条件的变化对干燥后的前胡切片香豆素类成分含量影响均不显著。Weibull函数模拟与分析结果表明：不同干燥条件下的尺度参数介于17.43~45.38，其值越小干燥时间越短，形状参数介于1.41~1.77且均大于1，表明干燥过程由内外部水分扩散共同控制。结论 研究工作既为前胡切片微波真空干燥的工艺改进和质量控制提供了重要的理论依据和技术支持，还将为前胡切片干燥的规范化和品质特征的形成提供重要参考。

Abstract:

OBJECTIVE In order to explore the moisture and components change law of Peucedani Radix slices during microwave vacuum drying, and effectively improve the drying efficiency and slice quality of Peucedani Radix slices, drying characteristics analysis and simulation of Peucedani Radix Slices during microwave vacuum drying were carried out. METHODS Microwave vacuum drying experiments of Peucedani Radix slices under different drying conditions (microwave power density, vacuum degree and slice thickness) were carried out. The changes of moisture ratio and drying rate during drying process were studied. The contents of three coumarin ingredients (praeruptorin A, praeruptorin B and praeruptorin E) in dried Peucedani Radix slices were determined by HPLC. Weibull function was used to simulate and analyze the moisture ratio curve during drying process. RESULTS The results showed that microwave vacuum drying process of Peucedani Radix slices has three stages: acceleration, constant speed and deceleration. Compared with vacuum degree and slice thickness, increasing microwave power density can shorten drying time and improve drying efficiency more effectively. In the range of experimental parameters, the optimum drying conditions were as follows: microwave power density was 3.0 W/g, vacuum degree was 800 Pa, and slice thickness was 2 mm. The changes of all drying conditions had no significant effect on the content of coumarins in dried Peucedani Radix slices. The results of Weibull function simulation and analysis showed that the scale parameters under different drying conditions ranged from 17.43 to 45.38, and the smaller the value, the shorter the drying time. The shape parameters ranged from 1.41 to 1.77 and were all greater than 1, indicating that the drying process was controlled by internal and external water diffusion. CONCLUSION The research work not only provides important theoretical basis and technical support for the process improvement and quality control of microwave vacuum drying process of Peucedani Radix slices, but also provides important reference for the standardization of Peucedani Radix slices drying and the formation of quality characteristics.