Standardization and application of methods to measure antioxidant capacity of foods and functional food components

Abstract

The functionality and content of functional components in foods need to be measured precisely. We have improved methods to evaluate the antioxidant capacity of foods based on oxygen radical absorbance capacity, and the content of quercetin in onions and isoflavones in soybeans. The precision of these methods was validated by inter-laboratory tests in accordance with internationally standardized protocols. These methods enable precise evaluation of antioxidant capacity and content, and the values are comparable. In this review article, the validated methods are introduced and the possible applications of the methods are discussed.