2.1. Chemicals
1,1-diphenyl-2-picrylhydrazyl (DPPH); 6-hydroxy-2,5,7,8-tetramethylchroman-
2-carboxylic acid (Trolox), Folin–Ciocalteu reagent,
acetonitrile (gradient grade for HPLC) and formic acid (98–100%)
were acquired from Sigma (Germany, Schnelldorf). Cyanidin 3-
glucoside and phenolic acid standards were purchased from Extrasynthese
(France, Genay). All reagents were of analytical grade.