表没食子儿茶素没食子酸酯(EGCG)在超声场中热稳定性的动力学  

Kinetic Modeling of the Thermal Stability of EGCG in an Ultrasonic Filed

作　　者：许楠[1] 卓雅[1] 曹雁平[1,2] 肖俊松[1,2] 吴葛洋[1] 

机构地区：[1]北京工商大学食品学院,北京100048 [2]食品添加剂与配料北京市高校工程研究中心,北京100048

出　　处：《食品科学》2011年第21期86-90,共5页Food Science

基　　金："十二五"国家科技支撑计划项目(2011BAD23B02)

摘　　要：研究弱酸环境下pH值对表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)的影响,以及在非超声场和0.25W/cm2、135kHz超声场中EGCG的稳定性,利用高效液相色谱对其进行定量分析。结果显示:温度为20℃、相同pH值时超声场中EGCG的稳定性均低于非超声场;pH6.2、超声40min时EGCG的损失率为10.70%,是非超声场的5.63倍。通过线性回归计算,确定EGCG在非超声场及超声场中的反应均符合一级反应动力学规律。超声场中,EGCG的反应速率常数为0.00228min-1,是非超声场的4.3倍;反应活化能为22861.13kJ/mol,比非超声场降低了14.0%;指前因子为28.30s-1,比非超声场提高了13.5%。In this study the stability of epigallocatechin gallate（EGCG） in a weakly acidic environment alone and in combination with an ultrasonic filed of 0.25 W/cm2 and 135 kHz was quantitatively analysis by high performance liquid chromatography.It was shown that under 20 ℃ and the same pH conditions,ultrasonic treatment caused a decrease of the stability of EGCG,and the loss rate of EGCG was 10.70 %,after 40 min exposure to pH 6.2 with ultrasonic treatment,exhibiting a 5.63-fold increase compared to the absence of ultrasonic.Linear regression indicated that the reaction of EGCG in an ultrasonic field and in a non-ultrasonic field followed first-order kinetics.The rate constant was 0.00228 min-1 in the presence of ultrasonic,the activation energy 22861.13 kJ/mol,and the pre-exponential factor 28.30 s-1,which were increased 4.3 times,decreased by 14.0% and increased by 13.5%,respectively.

关 键 词：表没食子儿茶素没食子酸酯 超声 稳定性 化学动力学 模型 

分 类 号：TS201.3[轻工技术与工程—食品科学]