荠菜过氧化物酶热失活动力学的研究

Thermal inactivation kinetics of peroxidase from Capsella bursa-pastoris

中文关键词:  荠菜  过氧化酶  酶活  热失活动力学

英文关键词:Capsella bursa-pastoris  peroxidase  enzyme activity  thermal inactivation kinetics

中文摘要:

      目的 研究不同温度、时间条件下热烫处理对荠菜中过氧化物酶(peroxidase, POD)活性的影响, 探究其失活动力学的变化规律。方法 荠菜在80、85、90、95、100℃的恒温热水中烫漂一定时间, 测定烫漂后POD的活性, 并采用一级动力学模型对POD热失活动力学进行拟合, 分析POD的反应活化能, 不同温度下失活速率常数(k值)和D值。结果 在80~100℃处理范围内, 随着处理温度的上升, 荠菜POD失活速率常数k值从0.01702 s?1增加到0.14260 s?1, D值从135.28702 s降低到16.14716 s, 反应活化能为114.00 kJ/mol。一级动力学模型拟合决定系数大于0.99。结论 热烫处理能有效钝化新鲜荠菜POD活性, 随着温度的上升, POD酶活性钝化效果明显, 荠菜POD的热失活动力学规律符合一级动力学模型。

英文摘要:

      Objective To study the effect of blanching on peroxidase (POD) activity in Capsella bursa-pastoris under different temperature and time conditions, and to explore the change of inactivation mechanism of POD. Methods The activity of POD was measured after blanching in hot water at 80, 85, 90, 95 and 100℃ for a certain time. A first-order kinetic model was used to fit the thermal inactivation kinetics of POD. The activation energy of POD, the rate constant of inactivation (k value) and D value of POD at different temperatures were analyzed. Results In the range of 80?100℃, with the increase of treatment temperature, the POD inactivation rate constant k value increased from 0.01702 s?1 to 0.14260 s?1, D value decreased from 135.28702 s to 16.14716 s, and the activation energy was 114.00 kJ/mol. The fitting determination coefficient of the first-order dynamic model was greater than 0.99. Conclusion Blanching can effectively inhibit the POD activity of fresh Capsella bursa-pastoris. With the increase of temperature, the activity of POD enzyme is obviously inhibited. The kinetics of heat inactivation of Capsella bursa-pastoris is in accordance with the first-order kinetic model.