Abstract
Numerous standardized methods for evaluating antioxidant capacity are available, some of the most used methods in this regard employ stable free radicals, like 2,2-diphenyl-1-picrilhydrazyl free radical (DPPH·) or 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid cation radical (ABTS·(+)). However, some challenges can arise in taking correct and reproducible measurements due to the well-known unspecific reactivity of these free radicals. In pursuit of improving and expanding such methods, in this work is proposed a highly intense colored zwitterionic derivative of the DPPH· free radical, as a replacement for DPPH· and ABTS·(+) derivatives. A discussion and comparison of the recognized methods are presented, demonstrating the very good potential of this non-radical compound.