摘要
目的:研究热风干燥过程中榆叶叶黄素的降解动力学。方法:采用高效液相色谱法测定榆叶中叶黄素的含量,对叶黄素降解过程进行反应动力学方程拟合,求解降解动力学参数。结果:新鲜榆叶中叶黄素含量较高,为(397.5±27.5)μg/g鲜质量((1.414±0.105)mg/g干质量)。当风速为0.5m/s,干燥温度为50、60、70℃时,榆叶中叶黄素的热降解符合一级反应动力学模型,半衰期分别为4.5、3.2、2.8h;温度升高,降解反应速率增大;降解反应速率常数与干燥温度的关系符合Arrhenius公式,反应活化能为21.23kJ/mol。结论:热风干燥榆叶时,采用较低的干燥温度有利于提高叶黄素保留率。
Purpose: This study aimed to determine the degradation kinetics of lutein in elm leaves during hot air drying process at different drying temperatures. Methods: The content of lutein in elm leaves was determined by high performance liquid chromatography(HPLC). The process of lutein degradation was fitted with a reaction kinetic equation and the degradation kinetic parameters were resolved. Results: The content of lutein in elm leaves was(397.5 ± 27.5) μg/g fresh weight(FW) or(1.414 ± 0.105) mg/g dry weight(DW). Analysis of kinetic data suggested a first-order reaction for the degradation of lutein in elm leaves with the half-lives of 4.5, 3.2 and 2.8 h at 50, 60 and 70 ℃, respectively. Increasing temperatures from 50 to 70 ℃ enhanced the degradation of lutein during drying process. The temperature-dependent degradation was adequately modeled on the Arrhenius equation. The activation energy value for the degradation of lutein in elm leaves was 21.23 kJ/mol. Conclusion:Hot-air dried elm leaves at lower temperature can retain higher levels of lutein.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2014年第11期6-10,共5页
Food Science
基金
国家自然科学基金面上项目(31171723)
关键词
榆叶
叶黄素
高效液相色谱法
降解动力学
elm leaves
lutein
high performance liquid chromatography
degradation kinetics
