Oxidized catechin
(D1ox) was obtained by stocking a catechin (D1) solution
(3 mg mL1 in phosphate buffer pH 6.5, 50 mM) at 28 C for 7 days.
To obtain oxidized apple tannins (A15box), 33 mg of apple tannins
(A15b) were solubilized in 11 mL of filtered (0.22 lm) phosphate
buffer (pH 6.5, 50 mM), and left in contact with air during 15 days
at 28 C. The buffers were filtered in order to minimize the risks of
bacterial growth.