Antioxidant Capacity of Teas and Herbal Infusions: Polarographic Assessment

作者：Gorjanovic Stanislava^*; Komes Drazenka; Pastor Ferenc T; Belscak Cvitanovic Ana; Pezo Lato; Hecimovic Ivana; Suznjevic Desanka

来源：Journal of Agricultural and Food Chemistry, 2012, 60(38): 9573-9580.

DOI：10.1021/jf302375t

• tea
• herbal infusions
• mate
• antioxidant activity
• hydrogen peroxide
• DC polarography

Hydrogen peroxide scavenging (HPS) activity of unfermented (green, yellow, and white), partially fermented (oolong), and completely fermented (black) tea (Camellia sinensis), mate (Ilex paraguariensis), and various herbal infusions, as well as individual compounds (flavan-3-ols, flavonols, cinnamic and benzoic acids, and methylxanthines), was assessed by recently developed direct current (DC) polarographic assay. Correlations of tea and herbal infusion HPS activity with total phenolic content determined using the Folin-Ciocalteu assay (FC-GAE) (0.81 and 0.93), ferric reducing/antioxidant power (FRAP) (0.97 and 0.92), 1,1-diphenyl-2-picrylhydrazyl (DPPH) (0.77 and 0.80), and 2,2%26apos;-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) scavenging (0.86 and 0.86) were statistically significant. Correlations between relative antioxidant capacity index (RACI), calculated by assigning all applied assays equal weight, and HPS (0.98), FRAP (0.97), ABTS (0.89), and DPPH (0.89) confirmed DC polarographic assay reliability when applied individually. Correlation analysis, ANOVA, and Levene and Tukey%26apos;s HSD tests unequivocally confirmed this reliable, rapid, and low-cost assay validity, clearly demonstrating its advantages over spectrophotometric assays applied.

• 出版日期2012-9-26