Degradation kinetics and isomerization of 5-O-caffeoylquinic acid under ultrasound: Influence of epigallocatechin gallate and vitamin C.
Degradation kinetics and isomerization of 5-O-caffeoylquinic acid under ultrasound: Influence of epigallocatechin gallate and vitamin C.
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超声下 5-O-咖啡酰奎尼酸的降解动力学和异构化：表没食子儿茶素没食子酸酯和维生素 C 的影响
DOI：
10.1016/j.fochx.2021.100147
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发表时间：
2021-12-30
期刊：
影响因子：
--
通讯作者：
Zheng F
中科院分区：
文献类型：
--
作者：
Wang D;Wang J;Sun J;Qiu S;Chu B;Fang R;Li L;Gong J;Zheng F
pH值的升高加速了5 - O - 咖啡酰奎宁酸（5 - CQA）的降解。在中性和碱性条件下，发现5 - CQA会发生异构化。超声促进了5 - CQA的降解和异构化。表没食子儿茶素没食子酸酯（EGCG）和维生素C（VC）减缓了超声诱导的5 - CQA的降解。
5 - O - 咖啡酰奎宁酸（5 - CQA），又称绿原酸，具有多种生物活性。因此，人们对其在加工和提取过程中性质变化的关注度有所提高。本研究考察了超声在不同pH值（pH 4.69、7.09、7.69和9.22）下对5 - CQA在水及50%甲醇 - 水体系中稳定性的影响。在处理过程中，对包括溶剂、超声功率、时间、温度、占空比和液高等不同参数进行了研究。结果表明，超声加速了5 - CQA的降解。基于威布尔模型对降解动力学进行了描述。降解速率常数（k）随pH值升高而增大，表明5 - CQA对碱敏感。在中性和碱性条件下，5 - CQA会异构化为3 - O - 咖啡酰奎宁酸和4 - O - 咖啡酰奎宁酸，超声进一步促进了这种异构化。分别添加表没食子儿茶素没食子酸酯（EGCG）和维生素C（VC）可提高5 - CQA的稳定性。
The increase of pH accelerated the degradation of 5-CQA. The isomerization of 5-CQA was found at neutral and alkaline conditions. Ultrasound boosted the degradation and isomerization of 5-CQA. EGCG and VC slowed down the degradation of 5-CQA induced by ultrasound. 5-O-Caffeoylquinic acid (5-CQA), also known as chlorogenic acid, exhibits various biological activities. Hence the interest in its property change during processing and extraction has increased. The present work studied the influence of ultrasound on the stability of 5-CQA at different pH (pH 4.69, 7.09, 7.69 and 9.22) in water and 50% methanol-water system. Different parameters including solvent, ultrasonic power, time, temperature, duty cycle, and liquid height were investigated during the treatment. Results indicate that ultrasound accelerated the degradation of 5-CQA. Based on Weibull model, the degradation kinetics were described. The rate constant (k) of the degradation increased with the increasing pH, demonstrating the alkali sensitivity of 5-CQA. The isomerization of 5-CQA to 3- and 4-O-caffeoylquinic acid was found at neutral and alkaline conditions, which was further boosted by ultrasound. The stability of 5-CQA was improved by adding epigallocatechin gallate (EGCG) and vitamin C (VC) respectively.