Kinetic Study of Catechin Stability: Effects of pH, Concentration, and Temperature
Kinetic Study of Catechin Stability: Effects of pH, Concentration, and Temperature
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DOI：
10.1021/jf304116s
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发表时间：
2012-12-26
影响因子：
6.1
通讯作者：
Mauer, Lisa J.
中科院分区：
文献类型：
--
作者：
Li, Na;Taylor, Lynne S.;Mauer, Lisa J.
儿茶素在包括茶饮料和儿茶素溶液在内的稀水体系中的降解行为已有文献记载，但它们在绿茶浓缩液中的反应动力学以及pH、浓度和温度对其影响的研究尚未建立。在本研究中，反应在pH值为1.5时至7，浓度为1至1666.7毫克/毫升，温度为25至120摄氏度的条件下进行，儿茶素的含量用高效液相色谱法测定。儿茶素在pH值为4时较稳定。建立了儿茶素含量随pH和温度变化的经验模型，结果表明绿茶浓缩液与以往报道的儿茶素在粉末体系中的稳定性有很好的相关性。这些结果为绿茶浓缩液在给定温度和pH条件下的货架期计算和儿茶素损失预测提供了有用的方法。
The degradation behaviors of catechins in dilute aqueous systems, including tea beverages and catechin solutions, have been documented; however, their reaction kinetics in green tea concentrated solutions, and impacts of pH, concentration, and temperature thereon, have not yet been established. In this study, reactions were conducted at pH levels ranging from 1.5 to 7, concentrations ranging from 1 to 1666.7 mg/mL, and temperatures ranging from 25 to 120 degrees C. Catechin contents were determined using high-performance liquid chromatography. Catechins were found to be more stable at high concentrations around pH 4. An empirical model for catechin content was established as a function of pH and temperature and showed good correlation between green tea concentrated solutions and previous reports of catechin stability in powder systems. These results provide useful approaches for shelf life calculations and catechin loss predictions at given temperature and pH conditions in green tea concentrates.