Abstract

Polyphenols are the second largest abundant organic molecules in nature. One of the principal reported biological activities is the antioxidant capacity. 2,2-Diphenyl-1-picrylhydracyl (DPPH) method has been used to quantify polyphenols antioxidant activity in many different products with reproducible and reliable results. We proposed and validated a methodology to analyze this antioxidant activity with smaller amount of sample and reagents, using DPPH. Technique validation was done through three ways: 1) between reported and proposed methodologies, 2) in the micro-plate assay and 3) between two different laboratories. Results between methods showed no significant differences. Results at different times, in the same day, had differences. Intra-day proposed assay results showed significant differences in days, turn and standard concentration; at the same time, no significant differences were found in sample solutions. Analysis from two different laboratories was validated. This result confirms that microscale DPPH scavenging quantification is a reliable alternative to save reactants and time.

Key words: Antioxidant activity, 2,2-diphenyl-1-picrylhydracyl (DPPH), micro plates, polyphenols.

Abbreviation

HAT, Hydrogen atom transfer; ET, electron transfer; ABTS, 2,2´-azino-bis(3-ethylbenzothiazoline-6-sulhonic acid); DPPH, 2,2-diphenyl-1-picrylhydracyl; ppm, parts per million; ANOVA, analysis of variance; H⁺, hydrogen ions.