超声提取石榴皮多酚的传质动力学模型研究

Mass Transfer Kinetics Model of Ultrasonic Extraction of Pomegranate Peel Polyphenols

目的:基于Fick第二定律传统理论,建立超声提取石榴皮多酚的传质动力学模型。方法:选择球形模型,以石榴皮多酚的质量浓度为考察指标,50%乙醇为提取溶剂进行超声提取,在不同的料液比、提取温度和提取时间下,对提取过程中的速率常数(k)、相对萃余率、表面扩散系数(DS)、半衰期(t1/2)和表观活化能(Ea)等动力学参数进行求解。结果:动力学参数中,随着提取温度的升高,k和DS逐渐增大,而t1/2逐渐减小,表明升高温度有利于石榴皮多酚的提取;相对萃余率指数方程求解表明,建立的石榴皮多酚提取动力学模型与实际测定的真实数值拟合良好,该模型能够很好的反映工艺条件与石榴皮多酚质量浓度之间的函数关系。结论:在实验基础上,建立超声提取石榴皮多酚的传质动力学模型可行、可靠,可用于工程放大生产中的优化控制。

Objectlve：The dynamic mathematical model of ultrasonic extraction of polyphenols from pomegranate peel was con- structed with the Fick＇s second law as the theoretical basis. Methods：The spherical model was selected, with mass concentrations of pomegranate peel polyphenols as the index,50% ethanol as the extraction solvent and ultrasonic extraction as the extraction method. In different test conditions including the liquid ratio, extraction temperature and extraction time, a series of kinetic parameters were solved, such as the extraction process （k） , relative raffinate rate, surface diffusion coefficient （Ds ）, half life （t~/2 ）and the apparent activation en- ergy（E,）. Results：With the extraction temperature increasing,k and Ds were gradually increased with tl/2 decreasing, which indicated that the elevated temperature was favorable to the extraction of pomegranate peel polyphenols. The exponential equation of relative raffi- nate rate showed that the established numerical dynamics model fitted the extraction of pomegranate peel polyphenols,and the relation- ship between the reaction conditions and pomegranate peel polyphenols concentration was well reflected by the model. Conclusion：Based on the experimental results, a feasible and reliable kinetic model for ultrasonic extraction of polyphenols from pomegranate peel is estab- lished, which can be used for the optimization control of engineering magnifying production.