Shimamura Tomoko, Sumikura Yoshihiro, Yamazaki Takeshi, Tada Atsuko, Kashiwagi Takehiro, Ishikawa Hiroya, Matsui Toshiro, Sugimoto Naoki, Akiyama Hiroshi, Ukeda Hiroyuki
Faculty of Agriculture, Kochi University.
Anal Sci. 2014;30(7):717-21. doi: 10.2116/analsci.30.717.
An inter-laboratory evaluation study was conducted in order to evaluate the antioxidant capacity of food additives by using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Four antioxidants used as existing food additives (i.e., tea extract, grape seed extract, enju extract, and d-α-tocopherol) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) were used as analytical samples, and 14 laboratories participated in this study. The repeatability relative standard deviation (RSD(r)) of the IC50 of Trolox, four antioxidants, and the Trolox equivalent antioxidant capacity (TEAC) were 1.8-2.2%, 2.2-2.9%, and 2.1-2.5%, respectively. Thus, the proposed DPPH assay showed good performance within the same laboratory. The reproducibility relative standard deviation (RSD(R)) of IC50 of Trolox, four antioxidants, and TEAC were 4.0-7.9%, 6.0-11%, and 3.7-9.3%, respectively. The RSD(R)/RSD(r) values of TEAC were lower than, or nearly equal to, those of IC50 of the four antioxidants, suggesting that the use of TEAC was effective for reducing the variance among the laboratories. These results showed that the proposed DPPH assay could be used as a standard method to evaluate the antioxidant capacity of food additives.
为了通过1,1-二苯基-2-苦基肼（DPPH）法评估食品添加剂的抗氧化能力，开展了一项实验室间评估研究。选用4种作为现有食品添加剂使用的抗氧化剂（即茶提取物、葡萄籽提取物、蒽提取物和d-α生育酚）以及6-羟基-2,5,7,8-四甲基色满-2-羧酸（Trolox）作为分析样品，14个实验室参与了本研究。Trolox、4种抗氧化剂的半数抑制浓度（IC50）以及Trolox等效抗氧化能力（TEAC）的重复性相对标准偏差（RSD(r)）分别为1.8-2.2%、2.2-2.9%和2.1-2.5%。因此，所提出的DPPH法在同一实验室中表现良好。Trolox、4种抗氧化剂的IC50以及TEAC的再现性相对标准偏差（RSD(R)）分别为4.0-7.9%、6.0-11%和3.7-9.3%。TEAC的RSD(R)/RSD(r)值低于或几乎等于4种抗氧化剂IC50的RSD(R)/RSD(r)值，这表明使用TEAC对于减少各实验室之间的差异是有效的。这些结果表明，所提出的DPPH法可作为评估食品添加剂抗氧化能力的标准方法。
