Effect of Enzymatic Digestion, pH and Molecular Weight on the Iron Solubilizing Properties of Chicken Muscle

The effects of a simulated gastrointestinal pH, enzymatic digestion and molecular weight (MW) on the iron solubilizing properties of a heated dilute salt insoluble fraction of chicken muscle were examined. The solubility of 50 ppm added FeCl 3 increased linearly from 0–260 min during pepsin digestion. The total soluble iron reached a maximum concentration following a 120 min pepsin‐30 min pancreatin digestion, with pepsin digestion products ranging in MW from 6200–2500. Solubilization capacity, defined as an in vitro measure of total iron bioavailability, did not correlate to binding by free sulfhydryl groups. The soluble low molecular weight iron chelates found may explain, in part, the mechanism by which the “meat factor” enhances iron bioavailability.