Abstract

GARCIA-MARQUEZ, E. et al. Effect of solvent-temperature extraction conditions on the initial antioxidant activity and total phenolic content of muitle extracts and their decay upon storage at different pH. Rev. Mex. Ing. Quím [online]. 2012, vol.11, n.1, pp.1-10. ISSN 1665-2738.

The effect of sotvent and extraction temperature on the initial antioxidani activity (AA) and total phenolic content (TPC) of Muitle (Justicia spicigera) extracts and their decay upon storage at different pH values was studied. Extraction with aqueous solvents, at either 25 or 60 °C, produced fresh extracts (pH 7.4) with higher initial TPC and AA. Extracts were adjusted to different pH's displayed different TPC and AAA dec ay rates upon storage. TPC had fiest order decay kinetics, characterized by e relatively quick constant (k₁) at relatively short storage times followed by a relatively slow constant (k₂) at relatively large storage times. ABTS and DPPH assays estimated different AA in the extracts, attributed to compatibility differences between the bioactive species and the free radicals.

Keywords : Justicia spicigera; total phenolic content; antioxidant activity; extraction conditions; decay kinetics.

        · abstract in Spanish     · text in English     · English ( pdf )