Interaction mixtures (75 ml final volume) contained 50 ml of
saliva and 25 ml of native or macerated tannin solutions, which
were previously filtered with Durapore filter at 0.45 mm (Millipore;
Rome, Italy). Binding assays were performed in Eppendorfs maintained
at 37 C for 5 min. The mixture was then centrifuged at 4 C
for 10 min at 10,000 g. The electrophoretic analyses were performed
on the resulting supernatant.