超声功率、频率对姜黄素浸取的影响与动力学模型

Dynamic Model of the Ultrasound-Assisted Extraction of the Curcumin from Curcuma longa L and the Effects of Ultrasound Intensity and Frequency on the Extraction

以姜黄为原料,采用65%乙醇水溶液为溶剂,研究不同温度(293～353 K)、超声功率(0.05～0.45 W·cm-2)和超声频率(28 kHz、40 kHz、50 kHz、135 kHz)对姜黄素超声浸取过程的影响。基于Fick定律,采用分离变量法建立了姜黄素超声浸取动力学方程,模拟结果与实验数据吻合较好。与常规浸取相比,超声功率、超声频率使表观扩散系数Du′分别提高了17.3%～38.5%和18.3%～40.4%。增大超声功率使扩散系数Du和浓度影响系数ρu提高,但是对Du的影响比ρu大。提高超声频率使Du和ρu的增加幅度降低,影响程度比超声功率低,超声频率对Du的影响也比ρu大。探讨了超声频率影响浸取效果的可能原因。

The influences of temperature（293～353 K）,ultrasound intensity（0.05～0.45 W cm 2） and frequency（28 kHz,40 kHz,50 kHz,135 kHz） on the ultrasound-assisted extraction（UE） of curcumin from Curcuma longa L with 65% ethanol aqueous solution were investigated,respectively.According to the Fick law,the dynamic model of curcumin UE was deduced by using the separation of variables method,and the modified model obtained fits the experiment data well.Comparing to conventional extraction,ultrasound intensity and frequency increase the superfical diffusion coefficient（Du′） by 17.3%～38.5% and 18.3%～40.4%,respectively.A higher ultrasonic intensity results in the increase both the diffusion coefficient（Du） and the concentration-affective coefficient（ρu）.The influence of increasing the ultrasonic intensity on Du is stronger than that on ρu.But the increase of ultrasonic frequency results in the decrease of the increasing amplitude of Du and ρu,and with a stronger influence on Du than on ρu.The possible causation of frequency effects on the extraction was discussed.