34] Screening of dietary carotenoids and carotenoid-rich fruit extracts for antioxidant activities applying 2,2′-azinobis(3-ethylenebenzothiazoline-6-sulfonic acid radical cation decolorization assay

Abstract

Publisher Summary This chapter discusses the screening of dietary carotenoids and carotenoid-rich fruit extracts for antioxidant activities applying 2, 2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation decolorization assay. The decolorization of the ABTS radical cation is an efficient, accurate assay for screening the antioxidant activities of lipophilic substances and food extracts. The inhibitory response of the radical cation is proportional to the antioxidant concentration, and the time point selected (2.5 min) for the analysis explains that this is an ideal measuring point when the reaction is complete. Results for the carotenoids are of the same order as previously reported data using alternative systems for generating the ABTS.+ radical cation. It is essential to examine the relative bioavailability, absorption, and hypoactivity of dietary carotenoids and flavonoids/phenolics to understand the importance of these diverse nutritional components in the maintenance of health and disease prevention. The chapter concludes with a discussion of trolox reference standard for relative antioxidant activities.