Fig. 2. Bioavailable quebracho (A), tannic acid (B), and quinine (C) during in vitro digestion with kaolin and without (control). Kaolin adsorbed a significant percentage (^*P<0.05) of the bioavailable fraction of each compound studied except for calcium oxalate, which was insoluble. In fact, kaolin increased Ca precipitation, with Ca delivery exceeding the comminuted input: two-tailed t-test, t=2.6, P<0.02 (D). Values are means ± 1 S.D.