Kim Dae-Ok, Lee Ki Won, Lee Hyong Joo, Lee Chang Yong
Department of Food Science and Technology, Cornell University, Geneva, New York 14456, USA.
J Agric Food Chem. 2002 Jun 19;50(13):3713-7. doi: 10.1021/jf020071c.
To express the antioxidant capacity of plant foods in a more familiar and easily understood manner (equivalent to vitamin C mg/100 g), two stable radical species, ABTS()(-) and DPPH(), commonly used for antioxidant activity measurements, were employed independently to evaluate their efficacies using apple polyphenolic extracts and seven polyphenolic standards including synthetic Trolox. Their antioxidant activities were expressed as vitamin C equivalent antioxidant capacity (VCEAC) in mg/100 g apple or mg/100 mL of the reference chemical compounds in 10 and 30 min using the ABTS()(-) and DPPH() scavenging assays, respectively. The antioxidant capacity of Gala apples and seven phenolic standards, determined by both ABTS()(-) and DPPH() scavenging assays, showed a dose-response of the first-order. Fresh Gala apples had a VCEAC of 205.4 +/- 5.6 mg/100 g using the ABTS assay, and the relative VCEACs of phenolic standards were as follows: gallic acid > quercetin > epicatechin > catechin > vitamin C > rutin > chlorogenic acid > Trolox. With the DPPH radical assay, the VCEAC of fresh Gala apples was 136.0 +/- 6.6 mg/100 g, and the relative VCEACs of seven phenolic standards were, in decreasing order, as follows: gallic acid > quercetin > epicatechin > catechin > or = vitamin C > Trolox > rutin > chlorogenic acid. Because the ABTS assay can be used in both organic and aqueous solvent systems, employs a specific absorbance at a wavelength remote from the visible region, and requires a short reaction time, it is a more desirable method than the DPPH assay. Therefore, it is recommended that antioxidant capacity be expressed as vitamin C mg/100 g equivalent (VCEAC) using the ABTS assay.
为了以更常见且易于理解的方式（等同于每100克维生素C毫克数）来表示植物性食物的抗氧化能力，两种常用于抗氧化活性测量的稳定自由基ABTS(·-)和DPPH(·)被分别独立用于评估苹果多酚提取物和包括合成的Trolox在内的七种多酚标准品的功效。分别使用ABTS(·-)和DPPH(·)清除试验，在10分钟和30分钟时将它们的抗氧化活性表示为每100克苹果中维生素C当量抗氧化能力（VCEAC）毫克数或每100毫升参考化合物中的毫克数。通过ABTS(·-)和DPPH(·)清除试验测定的嘎啦苹果和七种酚类标准品的抗氧化能力呈一级剂量反应。使用ABTS试验，新鲜嘎啦苹果的VCEAC为205.4±5.6毫克/100克，酚类标准品的相对VCEAC如下：没食子酸＞槲皮素＞表儿茶素＞儿茶素＞维生素C＞芦丁＞绿原酸＞Trolox。用DPPH自由基试验，新鲜嘎啦苹果的VCEAC为136.0±6.6毫克/100克，七种酚类标准品的相对VCEAC由高到低依次为：没食子酸＞槲皮素＞表儿茶素＞儿茶素＞或 = 维生素C＞Trolox＞芦丁＞绿原酸。由于ABTS试验可用于有机和水性溶剂体系，在远离可见光区域有特定吸光度，且反应时间短，所以它比DPPH试验更可取。因此，建议使用ABTS试验将抗氧化能力表示为每100克维生素C毫克当量（VCEAC）。
