*2.1. Materials*

Phosphate buffered saline (PBS, 0.01 M), iron(III) chloride (tetrahydrate) were obtained from Sigma-Aldrich (Steinheim, Germany). AlamarBlue (Cell Viability Reagent) was obtained from Invitro-gen (Waltham, MS, USA). Hydrochloric acid and sodium hydroxide was purchased from Reakhim (Moscow, Russia) and used without further purification. WPI (BiPRO, Davisco Foods Int., Inc., Eden Prairie, MN, USA) with 97.7% protein and 75% BGL in dry matter (according to the specification) was used as described previously [6]. TAs (ALSOK 02; MW 1040 D; pentagalloyl glucose 20% by weight; ALSOK 04; MW 850 D) was purchased from Omnichem NV Belgium (Wetteren, Belgium). Millipore Milli Q water (18.2 MΩ cm<sup>−</sup>1) was used as an aqueous medium during all sets of experiments.
