摘要
在不同冲泡温度与时间条件下,通过紫外-可见分光光度计测定了黄金茶茶多酚、游离氨基酸的浸出变化规律,建立浸出动力学模型,并通过DPPH法、ABTS法测定茶汤抗氧化性能。结果显示,冲泡温度为60~90℃时,黄金茶茶汤中茶多酚、游离氨基酸含量及DPPH、ABTS清除率随温度升高而增加;冲泡时间为1~30min时,茶汤中的茶多酚、游离氨基酸浓度及DPPH、ABTS清除率随时间延长而增加,30min后趋于稳定。茶多酚、游离氨基酸的浸出遵循二阶动力学反应,温度与浸出速率常数k有良好的线性关系,茶多酚表观活化能为4.312 6×104 J/mol,游离氨基酸表观活化能为1.238 9×104 J/mol。
In different brewing temperature and time,the changes of tea polyphenols and free amino acids brewing from Xiangxi golden tea, which were detected by UV-visible spectrophotometer, was gotten,and the extraction kinetics model was established.The antioxidant properties were also determined by DPPH and ABTS clearance rate.Results,the concentration of tea polyphenols and free amino acids,DPPH and ABTS clearance rate increased with the brewing temperature rising 60~90 ℃,and the brewing time prolonged 1~30 min,and which tended to be stable after 30 min.The Extraction rate of the tea polyphenols and amino acids followed a second-order reaction,and the extraction rate constant k and temperature had a good linear correlation.The apparent activation energy of polyphenols and free amino acids were 4.312 6×104 J/mol and1.238 9×104 J/mol,respectively.
作者
陈亮
余佶
游湘淘
金旋鹭
丁家云
麻成金
姚茂君
CHEN Liang;YU Ji;YOU Xiang-tao;JIN Xuan-lu;DING Jia-yun;MA Chen-jin;YAO Mao-jun(Key Laboratory of Human Forest Products and Chemical Industry Engineering, Jishou University, Zhangjiajie,Hunan 427000, China;Institute of Tea Science, Jishou University, Jishou, Hunan 416000, China)
出处
《食品与机械》
北大核心
2019年第8期183-188,共6页
Food and Machinery
基金
吉首大学校级科研项目资助(编号:Jdy1841)
关键词
黄金茶
冲泡条件
茶多酚
游离氨基酸
浸出动力学
抗氧化性能
golden tea
brewing conditions
tea polyphenols
free amino acids
extraction kinetics
antioxidant properties
