*2.4. Antioxidant Analysis*

The antioxidant activity of the samples was evaluated by preparing the extract of the samples. The weighed sample (one gram) was refluxed twice with 80% acidified methanol for 3 h. The pooled extracts were centrifuged at 1600× *g* for 10 min (Sorvall ST 16R, Thermo

Fischer Scientific, Bremen, Germany), with the volume made up with aqueous methanol, and these extracts were stored in amber bottles at 4 ± 1 ◦C till further analysis.

The DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity was measured by using the method given by Herrara-Balandrano et al. [30]. The ferric reducing antioxidant power (FRAP) assay was performed as per the method given by Silva et al. [31] and the results are given as μmol ferrous sulphate equivalent (FSE)/100 g db. The 2-azinobis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical scavenging activity was determined according to the method of Udeh et al. [32] and the results were expressed as μmol Trolox equivalent (TE)/100 g. The ability to chelate ferrous ions was determined to elucidate the metal chelating activity (MCA) by following the method detailed by Jayawardena et al. [33] and the MCA was reported in percentage (%).
