2.6. Determination of antioxidant capacity
2.6.1. Ferric reducing/antioxidant power (FRAP)
The ferric reducing/antioxidant power (FRAP) assay was carried
out according to a standard procedure by Benzie and Strain (1996).
All measurements were performed in triplicate. Aqueous solutions
of FeSO4×7H2O (100–1000 μmol/L) were used for the calibration and
the results are expressed as mmol FeII/L.
2.6.2. ABTS radical scavenging assay
The Trolox equivalent antioxidant capacity (TEAC) of chocolate
extracts was also estimated by the ABTS radical cation decolorization
assay (Re et al., 1999). The results, obtained from triplicate analyses,
were expressed as Trolox equivalents, and derived from a calibration
curve determined for this standard (100–1000 μmol/L).