Unsaturated Iron‐Binding Capacity of Human Milk

Abstract

ABSTRACT The unsaturated iron‐binding capacity (UIBC) and lactoferrin concentration of human milk from early stages of lactation were determined. The UIBC decreased significantly (p < 0.01) from 342 μg Fe/100 ml at the early transitional stage to 261 μg Fe/100 ml at the transitional stage and 215 μg Fe/100 ml at the mature stage. The lactoferrin concentration decreased significantly (p < 0.01) from 406 mg/100 ml at the early transitional stage to 241 mg/100 ml at the mature stage. No significant diurnal variations in UIBC or lactoferrin concentration were noted. Approximately 60% of the UIBC was retained after three different pasteurization treatments while less than 40% of the lactoferrin was retained. Seventy‐five percent of the UIBC was retained after sterilization; however, lactoferrin was completely destroyed. After frozen storage, the UIBC of the initial sample increased by 37% while the lactoferrin concentration decreased by 30%. These results indicate that there is not a direct relationship between iron‐binding capacity and lactoferrin concentration.