Effect of tannic acid on properties of soybean (Glycine max) seed ferritin: A model for interaction between naturally-occurring components in foodstuffs

► Tannic acid (TA) had little effect on the primary and secondary structure of soybean seed ferritin (SSF). ► Addition of TA could change its tertiary/quaternary structures. ► Interaction between TA and SSF could induce SSF aggregation. ► Association of SSF caused by TA inhibited ferritin degradation by pepsin or trypsin. ► Iron release was faster with TA than with ascorbic acid.