摘要
【目的】探讨比较红茶、金线莲茶和多穗石柯茶水相提取物的体外抗氧化活性,为明确草本茶的抗氧化活性及进一步应用提供理论依据。【方法】以市售传统红茶、金线莲茶和多穗石柯茶为试验原料,经水相浸提后考察提取液对总抗氧化活性和不同自由基清除效果的影响,并检测主要理化成分多酚和总黄酮的含量,以及进行抗氧化活性与理化成分之间的皮尔逊相关性分析。【结果】红茶、金线莲茶、多穗石柯茶三种茶提取物的总抗氧化活性和清除自由基效果皆呈浓度依赖效应,浓度越高,活性越强。相比较来看,等剂量处理时(以30μL为例),总抗氧化活性和ABTS自由基清除率大小为红茶(12.25μmol·L^(-1)、76.73%)>多穗石柯茶(11.66μmol·L^(-1)、54.98%)>金线莲茶(10.01μmol·L^(-1)、40.26%);羟基自由基清除活性大小为多穗石柯茶(50.25%)>红茶(48.04%)>金线莲茶(35.12%);DPPH自由基清除率大小为红茶(IC50值61.78μL)>多穗石柯茶(142.23μL)>金线莲茶(240.21μL)。相关性分析表明,抗氧化活性变化趋势与其多酚和总黄酮含量相关,总抗氧化活性和ABTS自由基清除率与多酚含量呈显著(P<0.05)正相关(r=0.958和0.970),羟基自由基和DPPH自由基清除率与总黄酮含量呈显著(P<0.05)正相关(r=0.992和0.911)。【结论】红茶、金线莲茶、多穗石柯茶等三种茶提取液均具有一定的抗氧化活性,能清除DPPH、羟基、ABTS等在内的多种自由基。总体来看,红茶提取物抗氧化性最强,金线莲提取物最弱,且自由基种类不同,作用效果不尽相同,这与其含有的多酚含量和总黄酮含量呈相关性,这可为其进一步开发应用提供科学依据。
【Objective】In vitro antioxidant activities of the aqueous extracts of three commercially available different kinds of tea were analyzed.【Method】A traditional black tea(BT),the golden thread orchid tea(GTO),and a Lithocarpus polystachyus herbal tea(LP)were extracted with boiling water for measurements of total antioxidant activity(TAA),free radical scavenging rates(FRSR),and chemical composition.Correlations between the major physicochemical properties and antioxidant activities of the extracts were determined by Pearson analysis.【Result】(1)TAAs and FRSRs of the extracts increased with increasing concentration.(2)In 30μL of the extract,the ranking on TAA was BTE(12.25μmol·L^(-1))>LPE(11.66μmol·L^(-1))>GTOE(10.01μmol·L^(-1));that on ABTS-FRSR,BTE(76.73%)>LPE(54.98%)>GTOE(40.26%);and that on DPPH-FRSR,LPE(50.25%)>BTE(48.04%)>GTOE(35.12%).(3)The Pearson correlation analysis showed that the antioxidant activity closely related to the polyphenol and total flavonoid contents of the extracts;the TAA and ABTS-FRSR to the polyphenols;and hydroxyl and DPPH FRSRs to the total flavonoids.【Conclusion】The extracts of three different kinds of tea all exhibited in varying degrees of antioxidant and free radical scavenging abilities.Overall,BTE was the strongest and GTOE the weakest on antioxidant activity.The tea extracts varied significantly on their FRSRs due to vastly different contents of polyphenols and flavonoids.
作者
杨军国
林延忠
李凤霞
YANG Junguo;Lin Yanzhong;LI Fengxia(College of Biological Science and Technology,Minnan Normal University,Zhangzhou,Fujian 363000;Research Institute of Zhangzhou-taiwan Leisure Food and Tea Beverage,Zhangzhou,Fujian 363000;Research College of Food Science,Zhangzhou,Fujian 363000;Zhangzhou Zhengjian Mountain Tea Industry Co.,Ltd,Zhangzhou,Fujian 363714)
出处
《茶叶学报》
2025年第3期60-67,共8页
Acta Tea Sinica
基金
福建省自然科学基金项目(2021J01993)
闽南师范大学校长基金项目(KJ19010)。
关键词
茶提取物
抗氧化活性
清除自由基
Tea extract
antioxidant activity
free radical scavenging ability
