摘要
茶和咖啡是全世界消费最多的饮料。该工作利用电子自旋共振(ESR)技术和ABTS〔2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid)〕等方法,研究和比较了3种绿茶(龙井、碧螺春和毛峰)和3种咖啡的抗氧化活性,以及对ABTS+、DPPH、超氧阴离子、羟基自由基、单线态氧的清除作用和对脂质过氧化的抑制作用。利用高压液相色谱(HPLC)分析了绿茶中的抗氧化成分之一EGCG((-)-epigallocatechin gallate)和咖啡中的抗氧化成分之一绿原酸(chlorogenic acid5,CQA)的含量。结果发现,如果按每克剂量比较,对于清除ABTS+的能力而言,茶和咖啡水提取液对ABTS+清除能力各有千秋,咖啡水提取液的比龙井、毛峰水提取液的高,但与碧螺春无显著差异,咖啡B比咖啡A和C强;按每杯茶(3g/200mL)和咖啡(2.4g/200mL)对ABTS+的清除能力进行比较,咖啡的比龙井和毛峰的高但比碧螺春低,咖啡B比咖啡A和C强。对超氧阴离子、羟基和DPPH自由基及单线态氧的清除作用和对脂质过氧化的抑制作用的研究表明,如果按每克剂量比较,茶和咖啡水提取液没有明显区别;按每杯量进行比较时,茶水提取液比咖啡水提取液对自由基的清除能力稍强。HPLC结果表明,EGCG含量在毛峰中最高,5CQA含量在咖啡B中最高。该研究结果表明茶和咖啡中均含有丰富的抗氧化成分,并都具有较强的抗氧化活性和清除自由基能力。
Tea and coffee are popular drinks around the world. In the present work, the authors studied and compared the antioxidant capacities and free radical scavenging effects of 3 green teas （Longjing, Biluochun and Maofeng） and 3 coffees. ABTS （2,2＇-Azinobis（3-ethylbenzothiazoline-6-sulfonic acid）） was used to study the antioxidant capacities; superoxide anion, hydroxyl, DPPH and lipid free radicals and singlet oxygen were used to study free radical scavenging effects by electron spin resonance （ESR） techniques. EGCG （（-）-epigallocatechin gallate） in teas and 5CQA （chlorogenic acid） in coffees were analyzed by HPLC. For total antioxidant effect, if coffee and tea were compared at same dosage, all coffees were stronger than Longjing and Maofeng but showed no difference with Biluochun, coffee B was stronger than coffee A and coffee C. If they were compared at per-service size （one cup, 3 g/200 mL for tea and 2.4 g/200 mL for coffee）, the effects of coffees were stronger than Longjing and Maofeng but weaker than that of Biluochun, coffee B was stronger than coffee A and coffee C. For the scavenging effects on superoxide anion, hydroxyl and DPPH free radicals and singlet oxygen, if they were compared at same dosage, the effects of teas and coffees were similar with little difference, if they were compared at per-service size, the scavenging effects of the tea solutions were stronger than that of the coffees. HPLC results showed that EGCG was highest in Maofeng and 5CQA was highest in coffee B. From above results, it can be concluded that both coffee and tea show strong antioxidant ability and have rich antioxidants.
出处
《生物物理学报》
CAS
CSCD
北大核心
2008年第6期435-444,共10页
Acta Biophysica Sinica
关键词
绿茶
咖啡
抗氧化能力
自由基清除
健康
Tea
Coffee
Antioxidant ability
Free radical scavenging
Health
