title: Applicability of the DPPH assay for evaluating the antioxidant capacity of food additives - inter-laboratory evaluation study -.
abstract: 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.
authors.affiliation: Faculty of Agriculture, Kochi University.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shimamura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sumikura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Atsuko
authors.initials: A
authors.lastname: Tada
authors.forename: Takehiro
authors.initials: T
authors.lastname: Kashiwagi
authors.forename: Hiroya
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Toshiro
authors.initials: T
authors.lastname: Matsui
authors.forename: Naoki
authors.initials: N
authors.lastname: Sugimoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Akiyama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ukeda
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D001713:Biphenyl Compounds / Q000737:chemistry*; D002839:Chromans / Q000032:analysis; D005503:Food Additives / Q000032:analysis*; D016166:Free Radical Scavengers / Q000032:analysis; D010851:Picrates / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis; D015203:Reproducibility of Results; D014810:Vitamin E / Q000032:analysis
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002839:Chromans; D005503:Food Additives; D016166:Free Radical Scavengers; D010851:Picrates; D010936:Plant Extracts; D014810:Vitamin E; C004931:1,1-diphenyl-2-picrylhydrazyl; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid