Abstract

Determination of the antioxidant activity of flavonoids in red Cayena and Roselle flowers by chemiluminescence

Author(s): Jos�������© A.Murillo Pulgar�������­n, Luisa F.Garc�������­a Bermejo, ArmandoCarrasqueroDur�������¡n

This study proposes a simple and fast methodologyfor the estimation of the antioxidant activity (AA) of aqueous extract of flowers, based on the inhibition of the luminol chemiluminescence in a FIA system.At the optimumoperational conditions theAA of several common phenolic antioxidantsweremeasured in terms of the EC50 (concentration needed to reduce in 50% the CL of blank) by plotting the percentage ofCLinhibition (%Inh) against the logarithm of the antioxidant concentration, the resultswere ex-plainedonbasisof structure-reactivityrelationships.The methodwas evaluated determining the antioxidant activity of dried flowers of Hibiscus Rosa Sinenis and Hibiscus Sabdariffa,whichwere extractedwith ethanol andwater to dissolve the biophenols, flavonoids and anthocyanins.TheAAwasmeasured by the proposedmethod agreedwellwith the results obtained by the DPPH test suggesting that it can be used as a complementarymethodfor the evaluation ofhydrophobic substanceswith antioxidant properties.