῏Ί῜ῐῙῐ῍ῌ῎῍ῑ῕῏ῒῖῗῚ῍ΐῘ῔ * +῔ ῌ ῲ῔* + ῌ * + ῌ * , ῌ  * , ῌ  Ὼ* - ῌ `ΐ* . ῌ  * . ῌ * + * + ῸῸ Ὸ * , ῕΅῍ῳ  * - Ὸ ῸῸ Ὸ * . ῿ῸῸ῱Ὸ ῱Ὸ Comparison of Conventional Antioxidants Assays for Evaluating Potencies of Natural Antioxidants as Food Additives by Collaborative Study Tomoko Shimamura* +῔ , Ritaro Matsuura* + , Takashi Tokuda* + , Naoki Sugimoto* , , Takeshi Yamazaki* , , Hiroshi Matsufuji* - , Toshiro Matsui* . , Kiyoshi Matsumoto* . and Hiroyuki Ukeda* + * + Department of Bioresources Science, Faculty of Agriculture, Kochi University, ,** Monobe-B, Nankoku, Kochi 12-ῌ2/*, * , National Institute of Health Sciences, +ῌ+2ῌ+ Kamiyoga, Setagaya-ku, Tokyo +/2ῌ2/*+ * - Department of Food Science and Technology, College of Bioresource Sciences, Nihon University, +200 Kameino, Fujisawa, Kanagawa ,/,ῌ2/+* * . Division of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School Kyusyu University, 0ῌ+*ῌ+ Hakozaki, Higashi-ku, Fukuoka 2+,ῌ2/2+ ῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌ In recent years, there has been a need for a new quality criterion for antioxidants based on its anti- oxidative activity in Japan. In particular, novel o$cial methods of evaluating the antioxidative activities of food additives are required. In order to investigate the possibility of developing o$cial methods, the reproducibilities of three simple conventional antioxidant assays (DPPH assay, ABTS assay, and WST-+ assay) based on spectrophotometric detection were evaluated by collaborative study between three laboratories. DPPH and ABTS assays were performed to evaluate the antioxidant activity (TEAC, Trolox equivalent activity) of all nine antioxidants used in this study, whereas the WST-+ assay was suitable for evaluating the superoxide dismutase (SOD)-equivalent activity of seven antioxidants (excepting D-a- tocopherol and D-d-tocopherol). The HorRat values from the collaborative study revealed that the DPPH and ABTS assays showed higher reproducibility than the WST-+ assay. It was assumed that the lower reproducibility would be due to the measuring principle, because the WST-+ assay, unlike the DPPH and the ABTS assays, is a competitive enzyme assay. Based on the results, we concluded that the DPPH and ABTS assays would be candidates in validation studies of methods for the purpose of developing an o$cial methodology. (Received Jun. ,*, ,**1 ; Accepted Aug. 3, ,**1) Keywords : antioxidant, food additiveῌ antioxidative activity, radical scavenging activity, superoxide anion radical scavenging activity ῍ῌ῏ῌ῎ : ῌ ῌ Όῌ ΎῩῬΌῌ ῎Ὺ῎ῨῧῨ῭ΎῩῬΌ ῌ ῞ῐῖῥ῝ῤῌ  ῟´ῖῥῤ῍ ´῟ῌ  1 ῳῶῌ ῑΰῐῖῥ῝Ὶ Ῐῤ ῴ῟ῗ῝ῐῠΰῥ῝ῤῡ ῞ῤ῍ ῞ῌ ΏῚῼ῜ ῷῼῖῥ῝ῤ῍ Ῑ῰ῌ ´ῌ  ῏ῑ῞ῤῡῌ ῎ ῌ ῢ ῞ῤῚῠῌ ῎ Ώῤ ῦ῟ῗῚῷῼῥ῝ῤ῍ ῖ ΰῌ ῎ ῌ ῢΊΰ῟ῖῥ῝ * + * , * - * . ῔ ῕12-ῌ2/*,   ,** ῕+/2ῌ2/*+ ῾ ῐ῵ +ῌ+2ῌ+ ῕,/,ῌ2/+*  `ῌ +200 ῕2+,ῌ2/2+    0ῌ+*ῌ+ ῒῐCorresponding authorῑῌ tomokos@kochi-u.ac.jp Nippon Shokuhin Kagaku Kogaku Kaishi Vol. /., No. ++, .2,῏.21 (,**1) ῒΐ 482 ῐ 20 ῑ