Friday, July 13, 2007

New Parameter Introduced to Measure Antioxidative Efficiency of Propolis

Evaluation of Antioxidative Activity of Croatian Propolis Samples Using DPPH· and ABTS·+ Stable Free Radical Assays
Molecules, Issue 5 (May 2007) pages 932-1201

Abstract: Propolis is one of the richest sources of plant phenolics (flavonoids and phenolic acids), which are widely recognized as rather strong antioxidants. The aim of our work was to use colored stable free radical (DPPH· and ABTS·+) spectrophotometric and thin-layer chromatographic (TLC) assays to study the antioxidative behavior of the phenolics (caffeic acid, galangin and pinocembrin) most commonly present in Croatian propolis samples obtained from different Croatian regions.

We propose a mathematical model providing a more sophisticated interpretation of the obtained results and a new parameter named antioxidative efficiency (AOE) is introduced…

Explained numerically, AOE represents the absolute value of the first derivative of an absorbance curve in the point A0/e (where A0 is the absorbance measured at t = 0 and e is the natural logarithm base).

The advantage of this newly introduced parameter is that it provides an easy and accurate mutual comparison between the rates of antioxidative efficiency of different propolis samples…

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