title: Antioxidant activity of propolis extracts from Serbia: a polarographic approach.
abstract: Antioxidant activity (AO) of commercial propolis extracts (PEs), available on Serbian market, was determined by direct current (DC) polarography. Polarographic anodic current of 5.0 mmol L(-1) alkaline solution of H2O2 was recorded at potentials of mercury dissolution. Decrease of the current was plotted against the volume of gradually added PEs. The volume of PE causing 20% current decrease was determined from the linear part of the plot. Antioxidant activity was expressed in H2O2 equivalent (HPEq), representing the volume of PE that corresponds to 1.0 mmol L(-1) H2O2 decrease. Resulting HPEq ranged between 1.71±0.11 and 8.00±0.18 μL. Range of 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity was from 0.093±0.004% to 0.346±0.006%. Total phenolic content (TCP) of PE with superior AO activity was 5.31±0.05% g GAE, while the extract with the lowest activity contained 1.45±0.02% g GAE. Antioxidant activity, determined by polarographic method, was correlated with DPPH scavenging activity (R2=0.991) and TCP (R2=0.985). Validity of obtained results was further confirmed using ANOVA and post hoc Tukey HSD test.
authors: University of Belgrade, Vinča Institute of Nuclear Sciences, Chemical Dynamics Laboratory, P.O. Box 522, 11001 Belgrade, Serbia. npotkonjak@vin.bg.ac.rs
authors: Nebojša I
authors: NI
authors: Potkonjak
authors: Dragan S
authors: DS
authors: Veselinović
authors: Miroslav M
authors: MM
authors: Novaković
authors: Stanislava Ž
authors: SŽ
authors: Gorjanović
authors: Lato L
authors: LL
authors: Pezo
authors: Desanka Ž
authors: DŽ
authors: Sužnjević
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry; D005504:Food Analysis; D010084:Oxidation-Reduction; D010851:Picrates / Q000737:chemistry; D011048:Polarography / Q000379:methods*; D011429:Propolis / Q000737:chemistry*; D055771:Serbia
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D011429:Propolis; C004931:1,1-diphenyl-2-picrylhydrazyl