Interactions of Tannic Acid and Catechin with Legume Starches

ABSTRACT Model system interactions between five different legume starches (azuki red bean, split yellow pea, small red bean, bush bean, and California kidney bean), potato starch, amylose, and amylopectin and two phenolic compounds ‐ tannic acid and catechin ‐ were investigated. The amounts of tannic acid and catechin associated with different starches and starch fractions at room temperature (21°C) ranged, respectively, from 261‐652 and 123‐586 Mg catechin equivalents/100 mg starch. Heating the systems at 95°C for 30 min decreased the quantities of tannic acid and catechin associated with different starches (151‐417 and 147‐378 μg catechin equivalents/100 mg starch of tannic acid and catechin, respectively). Bound tannic acid and catechin decreased the in vitro digestibility of the starches.