Effects of iron alone and in combination with calcium, zinc and copper on the mineral-binding capacity of wheat bran

Extract: The addition of various combinations of iron, calcium, zinc and copper to soft white wheat bran (SWWB) and hard red spring wheat bran (HRSWB) was shown to effect both the solubility of added minerals and those occurring endogenously. The addition of equimolar concentrations of Fe and Zn resulted in a significant decrease in soluble iron of 5.4% and 9.0% for SWWB and HRSWB, respectively, and a significant decrease in soluble magnesium, compared to wheat bran systems with iron alone. However, when equimolar concentrations of Fe and Cu were added to the wheat bran systems, there was no significant effect on Fe solubility and a significant increase in Mg solubility. Further, the addition of Fe and Ca (160 mg) to the wheat bran systems caused a significant decrease in soluble iron of 12.0% for SWWB and 17.4% for HRSWB, and a significant increase in Mg solubility. These results suggest that there are mineral-specific binding sites in wheat bran.(author)