微波辅助萃取多物理场耦合模型的构建及验证

以姜科类植物草豆蔻中山姜素为模拟对象, 基于微波辅助萃取(MAE)过程中微波场、 温度场及浓度场等物理场之间的耦合关系, 利用Comsol软件构建了MAE多物理场耦合模型. 模拟了不同萃取时间、 微波功率下萃取体系的电磁场分布、 温度分布以及山姜素扩散分布; 通过比较萃取液温度和山姜素浓度的模拟值与实验值, 结合误差分析对模型进行了验证, 以同类植物砂仁中的异槲皮苷为萃取目标验证了模型的适用性. 结果表明, 微波功率越大, 电磁场强度越强, 萃取液温度越高, 山姜素扩散越明显, 越有利于萃取; MAE萃取山姜素和异槲皮苷的萃取液温度模拟值与实验值之间的相对均方根误差(RRMSE)分别在1.9%~4.5%和1.9%~2.8%之间, 其浓度RRMSE分别在1.7%~3.2%及1.6%~4.1%之间, 均小于5.0%, 表明建立的模型准确、 可靠, 且适用性良好. 该模型综合考虑了MAE过程中的多个物理场及其耦合关系, 可为深入研究其萃取机理提供参考.

Development and Validation of Multiple Physical Fields Coupling Model for Microwave-assisted Extraction

A multiple physical fields coupling model was developed using Comsol for microwave-assisted extraction（MAE） of alpinetin from Alpinia katsumadai Hayata， which was based on the coupling relations between the microwave field， temperature field and concentration field. And the model was used to simulate electromagnetic field distribution， temperature distribution and alpinetin diffusion distribution under different time and microwave powers. The model was verified by comparing the simulated and experimental values of extraction temperature and the concentration of alpinetin. Isoquercitrin in Amomum villosum， which belongs to the ginger family， was used as the target to further verify the applicability of the multiple physical fields coupling model. The results showed that the electromagne-tic field intensity was stronger， the temperature of the extraction solution was higher， and the diffusion of alpinetin was more obvious with the increase of microwave power， that was benefit to the extraction. The root relative mean square error（RRMSE） of extraction solution temperature between the simulated and experimental values for alpinetin and isoquercitrin was 1.9%—4.5% and 1.9%—2.8%， and concentration RRMSE was 1.7%—3.2% and 1.6%—4.1%， which were all less than 5.0%， indicating that the model was accurate and reliable. The model comprehensively considered multiple physical fields and the coupling relationships in the MAE process， which could provide a reference for further study of extraction mechanism.