The Behavior and Stability of Iron‐Ascorbate Complexes in Solution

ABSTRACT The thermodynamic stability constants for ferric and ferrous ascorbate complexes, change in net redox potential with pH, and efficacy of bathophenanthroline as an iron reagent in the presence of ascorbate were determined. The stability constants for the ferric and ferrous ascorbate complexes were found to be in the range 1.90 × 10 3 to 2.61 × 10 4 and 7.69 × 10 ‐3 to 6.95 × 10 ‐2 , respectively. The stability of ferric ascorbate over a wide range of pH values suggests its potential use as an iron additive in foods. Redox potential decreased with an increase in pH. Bathophenanthroline analysis of these solutions for free iron proved to have limitations in the presence of ascorbate.