2.7. Antioxidant activity determinations
2.7.1. ABTS assays
For ABTS assay, the procedure followed the method of Arnao,
Cano, and Acosta (2001) with some modifications. The stock solutions
included 7.4 mM ABTS+ solution and 2.6 mM potassium persulfate
solution. The working solution was then prepared by
mixing the two stock solutions in equal quantities and allowing
them to react for 12 h at room temperature in the dark. This solution
was then diluted by mixing 1 mL ABTS+ solution with 60 mL
methanol to obtain an absorbance of 1.1 ± 0.02 units at 734 nm
using the spectrophotometer. Fresh ABTS+ solution was prepared
for each assay. Fruit extracts (150 lL) were allowed to react with
2850 lL of the ABTS+ solution for 2 h in the dark. Then, the absorbance
was read at 734 nm using a spectrophotometer. The standard
curve was linear between 25 and 600 mM Trolox. Results
are expressed in lM Trolox equivalents (TE)/g dry mass, as means
of three replicates.
2.7.2. DPPH assay
The DPPH assay was performed according to the method of
Brand-Williams, Cuvelier, and Berset (1995) with some modifica-