Satoh Eiki, Tohyama Naoki, Nishimura Masakazu
Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan.
Int J Food Sci Nutr. 2005 Dec;56(8):551-9. doi: 10.1080/09637480500398835.
Although the antioxidant properties of green, oolong, and black teas have been well studied, antioxidant activity has not been examined in roasted tea. Therefore, in the current studies, we investigated the antioxidant activity of roasted tea in comparison with those of green, oolong, and black teas. Using water extracts of the various teas, we examined the total phenolic content as well as the antioxidant activities, including the reducing power, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and the inhibition of hemolysis caused by 2,2'-azo-bis(2-amidinopropane) dihydrochloride (AAPH)-induced lipid oxidation in erythrocyte membranes. The roasted tea contained lower levels of total phenolics than green, oolong, or black tea (green tea > oolong tea > black tea > roasted tea). The relative reducing power and DPPH scavenging activity decreased in the following order: green tea > roasted tea > oolong tea > black tea. Also, green tea was more effective against AAPH-induced erythrocyte hemolysis than other teas (green tea>roasted tea = oolong tea = black tea). These results suggest that roasted tea is beneficial to health, in humans, because of its high antioxidant activity.
尽管绿茶、乌龙茶和红茶的抗氧化特性已得到充分研究，但烘焙茶的抗氧化活性尚未得到检验。因此，在当前的研究中，我们将烘焙茶与绿茶、乌龙茶和红茶的抗氧化活性进行了比较。使用各种茶叶的水提取物，我们检测了总酚含量以及抗氧化活性，包括还原能力、1,1-二苯基-2-苦基肼（DPPH）自由基清除活性，以及对2,2'-偶氮二异丁脒盐酸盐（AAPH）诱导的红细胞膜脂质氧化所导致的溶血的抑制作用。烘焙茶的总酚含量低于绿茶、乌龙茶或红茶（绿茶>乌龙茶>红茶>烘焙茶）。相对还原能力和DPPH清除活性按以下顺序降低：绿茶>烘焙茶>乌龙茶>红茶。此外，绿茶在对抗AAPH诱导的红细胞溶血方面比其他茶叶更有效（绿茶>烘焙茶 = 乌龙茶 = 红茶）。这些结果表明，烘焙茶因其高抗氧化活性而对人体健康有益。
