利用Arrhenius动力学方程,研究了不同热处理(4～100℃)条件下,表没食子儿茶素没食子酸酯(EGCG)发生降解、异构化和脱没食子化反应的变化规律,并建立了相关的动力学预测模型。结果表明:热处理过程中EGCG发生的降解、异构化和脱没食子化反应均属于一级动力学反应,可用Arrhenius方程进行拟合(R2>0.9),反应速率常数K均随着温度的升高而增加,预测模型中的Ea(活化能)和A(频率因子)分别为53.90kJ/mol和5.698×104、98.60 kJ/mol和7.315×1012、85.34 kJ/mol和5.112×1010,表明EGCG易发生降解,而发生异构化反应难;各模型的预测值与实际值的相对误差<13%,因此可根据Arrhenius方程对热处理条件下EGCG的变化进行预测。

This paper studied the variation of degradation,epimerization and de-gallate acid reaction of Epigallocatechin Gallate(EGCG) under the conditions of different heat treatment(4～100 ℃) by using the Arrhenius equation,and established the related kinetic predicting model.The results showed that the degradation,epimerization and de-gallate acid reaction of EGCG complied with the first order reaction during heat treatment,the Arrhenius equation was able to be used to fit(R2> 0.9),the rate constants went up as the temperature raised.The Ea(activation energy) and A(frequency factor) in prediction model were 53.90kJ/mol and 5.698 × 104,98.60kJ/mol and 7.315 × 1012,85.34kJ/mol and 5.112 × 1010,respectively,which indicating that the degradation of EGCG was the most easily reaction,and epimerization of EGCG was the most difficult reaction;the relative error of the model predicted value and actual value was less than 13%.Therefore,the changes of EGCG was able to be predicted according to Arrhenius equation under the condition of heat treatment.