热烫处理对香椿叶绿素及颜色的影响

The Effects of Blanching on Chlorophyll and Color of Toona sinensis

为了研究香椿热烫过程中叶绿素和颜色的变化规律,分析不同热烫温度(85,90,95,100℃)对香椿叶绿素含量和色差值的影响,采用Hunter Lab表色系统测定颜色变化。结果表明,香椿叶绿素及颜色热稳定性较差;热烫温度愈高,叶绿素降解及颜色变化愈快;随热烫温度的升高和时间的延长,除a值降低外,L值和b值均呈现上升趋势;香椿叶绿素和颜色(a·b/L)的热降解均符合一级反应动力学模型,其反应活化能(E_a)分别为12.586 kJ/mol和53.351 kJ/mol;叶绿素含量与颜色(a·b/L)呈显著线性关系。适当降低热烫温度及缩短热烫时间,有利于保护香椿颜色,减少叶绿素损失。本研究结果为提高香椿加工品感官品质提供依据。

To investigate thermal degradation kinetics of chlorophyll and color of Toona sinensis during blanching,the effects of temperature on chlorophyll degradation and color loss were studied at 85,90,95 and 100 ℃,and color was determined by using Hunter Lab.Results showed that chlorophyll and color of Toona sinensis were instable to heat.The higher blanching temperature,the faster degradation of chlorophylls.Except for a reducing,L and b were raising with the increases of blanching temperature and the prolong of blanching time.Chlorophyll breakdown and color loss（a·b/L）followed a first-order reaction with the activation energy（Ea） of 12.586 kJ/mol and 53.351 kJ/mol respectively.Significant correlation between chlorophyll and a·b/L were found.It was suggested that moderately decreasing blanching temperature and time was favorable for protecting color and chlorophyll of blanched Toona sinensis.The results could provide technical basis for improving sensory quality.