L-Ascorbic acid was purchased from Sigma-Aldrich,DPPH (2,2-diphenyl-1-picrydrazyl) from Sigma Aldridge and ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid )) from Fluka. Ferric chloride, acetic acid and sodium acetate were obtained from Lach-Ner (Czech Republic). All chemicals used were p.a. purity or higher.