Standardized Methods for the Determination of Antioxidant Capacity and Phenolics in Foods and Dietary Supplements

• Published in: Journal of agricultural and food chemistry Vol. 53; no. 10; pp. 4290 - 4302
• Main Authors: Prior, Ronald L, Wu, Xianli, Schaich, Karen
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Washington, DC American Chemical Society 18-05-2005
• Subjects: antioxidant activity; antioxidants; Antioxidants - analysis; Antioxidants - chemistry; assays; Biological and medical sciences; Chromans - chemistry; dietary supplements; Dietary Supplements - analysis; Feeding. Feeding behavior; Fluorescent Dyes; Folin-Ciocalteu method; Food Analysis - methods; Food Analysis - standards; Food industries; foods; free radicals; functional foods; Fundamental and applied biological sciences. Psychology; Luminescent Measurements; Molybdenum; Oxidation-Reduction; oxygen radical absorbance capacity; phenolic compounds; Phenols - analysis; Photochemistry; Reactive Oxygen Species - chemistry; Reproducibility of Results; Research and development. New food products, dietetic foods and beverages; Trolox equivalent antioxidant capacity; Tungsten Compounds; Vertebrates: anatomy and physiology, studies on body, several organs or systems; dietary supplements; nutraceuticals; ORAC; Folin-Ciocalteu method; TEAC; Standardized methods; antioxidant capacity; foods; Phenols; Supplemented diet; Method; Antioxidant; Feeding; Food; Food supplement
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf0502698

Methods available for the measurement of antioxidant capacity are reviewed, presenting the general chemistry underlying the assays, the types of molecules detected, and the most important advantages and shortcomings of each method. This overview provides a basis and rationale for developing standardized antioxidant capacity methods for the food, nutraceutical, and dietary supplement industries. From evaluation of data presented at the First International Congress on Antioxidant Methods in 2004 and in the literature, as well as consideration of potential end uses of antioxidants, it is proposed that procedures and applications for three assays be considered for standardization:  the oxygen radical absorbance capacity (ORAC) assay, the Folin−Ciocalteu method, and possibly the Trolox equivalent antioxidant capacity (TEAC) assay. ORAC represent a hydrogen atom transfer (HAT) reaction mechanism, which is most relevant to human biology. The Folin−Ciocalteu method is an electron transfer (ET) based assay and gives reducing capacity, which has normally been expressed as phenolic contents. The TEAC assay represents a second ET-based method. Other assays may need to be considered in the future as more is learned about some of the other radical sources and their importance to human biology. Keywords: Standardized methods; antioxidant capacity; foods, dietary supplements; nutraceuticals; ORAC; Folin−Ciocalteu method; TEAC