Lee Ki Won, Kim Young Jun, Lee Hyong Joo, Lee Chang Yong
Department of Food Science and Technology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-742, South Korea.
J Agric Food Chem. 2003 Dec 3;51(25):7292-5. doi: 10.1021/jf0344385.
Black tea, green tea, red wine, and cocoa are high in phenolic phytochemicals, among which theaflavin, epigallocatechin gallate, resveratrol, and procyanidin, respectively, have been extensively investigated due to their possible role as chemopreventive agents based on their antioxidant capacities. The present study compared the phenolic and flavonoid contents and total antioxidant capacities of cocoa, black tea, green tea, and red wine. Cocoa contained much higher levels of total phenolics (611 mg of gallic acid equivalents, GAE) and flavonoids (564 mg of epicatechin equivalents, ECE) per serving than black tea (124 mg of GAE and 34 mg of ECE, respectively), green tea (165 mg of GAE and 47 mg of ECE), and red wine (340 mg of GAE and 163 mg of ECE). Total antioxidant activities were measured using the 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays and are expressed as vitamin C equivalent antioxidant capacities (VCEACs). Cocoa exhibited the highest antioxidant activity among the samples in ABTS and DPPH assays, with VCEACs of 1128 and 836 mg/serving, respectively. The relative total antioxidant capacities of the samples in both assays were as follows in decreasing order: cocoa > red wine > green tea > black tea. The total antioxidant capacities from ABTS and DPPH assays were highly correlated with phenolic content (r2 = 0.981 and 0.967, respectively) and flavonoid content (r2 = 0.949 and 0.915). These results suggest that cocoa is more beneficial to health than teas and red wine in terms of its higher antioxidant capacity.
红茶、绿茶、红酒和可可富含酚类植物化学物质，其中茶黄素、表没食子儿茶素没食子酸酯、白藜芦醇和原花青素，由于其基于抗氧化能力可能具有化学预防作用，已分别得到广泛研究。本研究比较了可可、红茶、绿茶和红酒的酚类和黄酮类含量以及总抗氧化能力。每份可可中的总酚类物质（611毫克没食子酸当量，GAE）和黄酮类物质（564毫克表儿茶素当量，ECE）含量远高于红茶（分别为124毫克GAE和34毫克ECE）、绿茶（165毫克GAE和47毫克ECE）和红酒（340毫克GAE和163毫克ECE）。使用2,2'-联氮-双-(3-乙基苯并噻唑啉-6-磺酸)（ABTS）和2,2-二苯基-1-苦基肼（DPPH）自由基清除试验测定总抗氧化活性，并表示为维生素C当量抗氧化能力（VCEAC）。在ABTS和DPPH试验中，可可在样品中表现出最高的抗氧化活性，VCEAC分别为1128和836毫克/份。两种试验中样品的相对总抗氧化能力按降序排列如下：可可＞红酒＞绿茶＞红茶。ABTS和DPPH试验的总抗氧化能力与酚类含量（r2分别为0.981和0.967）和黄酮类含量（r2分别为0.949和0.915）高度相关。这些结果表明，就其较高抗氧化能力而言，可可对健康比茶和红酒更有益。
