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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。
OBJECTIVE: To establish a mass transfer kinetic model of polyphenols extracted from pomegranate peel by ultrasonic extraction based on the traditional theory of Fick’s second law. Methods: The spherical model was selected. With the mass concentration of polyphenols in pomegranate peel as index, 50% ethanol was used as the extraction solvent for ultrasonic extraction. Under different extraction rates and extraction time, the rate constants k), relative raffinate ratio, surface diffusion coefficient (DS), half life (t1 / 2) and apparent activation energy (Ea) were calculated. Results: In the kinetic parameters, k and DS increased gradually with the increase of extraction temperature, while t1 / 2 decreased gradually, which indicated that increasing temperature was favorable for the extraction of polyphenols from pomegranate peel. The relative raffinate index equation was solved The results showed that the kinetic model of extraction of pomegranate peel polyphenols was fit well with the real values of pomegranate peel. This model can well reflect the functional relationship between the technological conditions and the concentration of polyphenols in pomegranate peel. Conclusion: Based on the experiment, it is feasible and reliable to establish the mass transfer kinetic model of polyphenols extracted from pomegranate peel by ultrasonic extraction, which can be used for the optimal control in engineering enlargement production.