A novel procedure to measure the antioxidant capacity of yerba mate extracts

作者：Graciela Hartwig Vanessa; Alberto Brumovsky Luis; Maria Fretes Raquel; Sanchez Boado Lucila

来源：Food Science and Technology, 2012, 32(1): 126-133.

DOI：10.1590/S0101-20612012005000022

• DPPH
• yerba mate
• antioxidant capacity
• Ilex paraguariensis

Yerba mate extracts have in vitro antioxidant capacity attributed to the presence of polyphenolic compounds, mainly chlorogenic acids and dicaffeoylquinic acid derivatives. DPPH is one of the most used assays to measure the antioxidant capacity of pure compounds and plant extracts. It is difficult to compare the results between studies because this assay is applied in too many different conditions by the different research groups. Thus, in order to assess the antioxidant capacity of yerba mate extracts, the following procedure is proposed: 100 mu L of an aqueous dilution of the extracts is mixed in duplicate with 3.0 mL of a DPPH %26apos;work solution in absolute methanol (100 mu M.L-1), with an incubation time of 120 minutes in darkness at 37 +/- 1 degrees C, and then absorbance is read at 517 nm against absolute methanol. The results should be expressed as ascorbic acid equivalents or Trolox equivalents in mass percentage (g% dm, dry matter) in order to facilitate comparisons. The AOC of the ethanolic extracts ranged between 12.8 and 23.1 g TE % dm and from 9.1 to 16.4 g AAE % dm. The AOC determined by the DPPH assay proposed in the present study can be related to the total polyphenolic content determined by the Folin-Ciocalteu assay.

• 出版日期2012-3